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Mori M, Takeshita S, Nakamura N, Mizuno Y, Tomita A, Aoyama M, Kakita H, Yamada Y. Efficacy of tolvaptan in an infant with syndrome of inappropriate antidiuretic hormone secretion associated with holoprosencephaly: A case report. World J Clin Cases 2023; 11:6262-6267. [PMID: 37731562 PMCID: PMC10507562 DOI: 10.12998/wjcc.v11.i26.6262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 07/31/2023] [Accepted: 08/15/2023] [Indexed: 09/08/2023] Open
Abstract
BACKGROUND Holoprosencephaly (HPE) is a congenital malformation with various degrees of incomplete separation of the cerebral hemispheres due to differentiation disorders of the forebrain. Although HPE with diabetes insipidus due to associated pituitary dysfunction has been reported, HPE with the syndrome of inappropriate antidiuretic hormone secretion (SIADH) is very rare. Tolvaptan, a vasopressin V2 receptor antagonist, is effective in adults with SIADH. However, there is no report of its efficacy in infants with SIADH. The purpose of this report is to demonstrate that tolvaptan is effective for SIADH in infants and that administration of tolvaptan eliminates the need for restriction of water intake and sodium administration. CASE SUMMARY A 2414-g female infant was born at 38 wk by normal vaginal delivery. Facial anomalies and head magnetic resonance imaging indicated semilobar HPE. After birth, she had hyponatremia due to SIADH and was treated using water and sodium restriction. However, she developed an exaggerated response to the fluid restrictions, resulting in large fluctuations in serum sodium levels. Subsequent administration of tolvaptan improved the fluctuations in serum sodium levels without the need for adjustment of water or sodium administration. Serum sodium was maintained within the normal range after discontinuation of tolvaptan at 80 d of life. There were no side effects, such as hypernatremia or liver dysfunction, during the administration of tolvaptan. CONCLUSION This is the first report on the safety and efficacy of tolvaptan in an infant with SIADH associated with HPE.
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Affiliation(s)
- Mari Mori
- Department of Perinatal and Neonatal Medicine, Aichi Medical University, Nagakute 480-1195, Japan
| | - Satoru Takeshita
- Department of Perinatal and Neonatal Medicine, Aichi Medical University, Nagakute 480-1195, Japan
- Department of Pathobiology, Nagoya City University Graduate School of Pharmaceutical Sciences, Nagoya 467-8603, Japan
| | - Nami Nakamura
- Department of Perinatal and Neonatal Medicine, Aichi Medical University, Nagakute 480-1195, Japan
- Department of Pediatrics, Aichi Medical University, Nagakute 480-1195, Japan
| | - Yuki Mizuno
- Department of Pharmacy, Aichi Medical University, Nagakute 480-1195, Japan
| | - Akiko Tomita
- Department of Pharmacy, Aichi Medical University, Nagakute 480-1195, Japan
| | - Mineyoshi Aoyama
- Department of Pathobiology, Nagoya City University Graduate School of Pharmaceutical Sciences, Nagoya 467-8603, Japan
| | - Hiroki Kakita
- Department of Perinatal and Neonatal Medicine, Aichi Medical University, Nagakute 480-1195, Japan
- Department of Pathobiology, Nagoya City University Graduate School of Pharmaceutical Sciences, Nagoya 467-8603, Japan
| | - Yasumasa Yamada
- Department of Perinatal and Neonatal Medicine, Aichi Medical University, Nagakute 480-1195, Japan
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Wong A, Zhou A, Cao X, Mahaganapathy V, Azaro M, Gwin C, Wilson S, Buyske S, Bartlett CW, Flax JF, Brzustowicz LM, Xing J. MicroRNA and MicroRNA-Target Variants Associated with Autism Spectrum Disorder and Related Disorders. Genes (Basel) 2022; 13:1329. [PMID: 35893067 PMCID: PMC9329941 DOI: 10.3390/genes13081329] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2022] [Revised: 07/19/2022] [Accepted: 07/22/2022] [Indexed: 12/13/2022] Open
Abstract
Autism spectrum disorder (ASD) is a childhood neurodevelopmental disorder with a complex and heterogeneous genetic etiology. MicroRNA (miRNA), a class of small non-coding RNAs, could regulate ASD risk genes post-transcriptionally and affect broad molecular pathways related to ASD and associated disorders. Using whole-genome sequencing, we analyzed 272 samples in 73 families in the New Jersey Language and Autism Genetics Study (NJLAGS) cohort. Families with at least one ASD patient were recruited and were further assessed for language impairment, reading impairment, and other associated phenotypes. A total of 5104 miRNA variants and 1,181,148 3' untranslated region (3' UTR) variants were identified in the dataset. After applying several filtering criteria, including population allele frequency, brain expression, miRNA functional regions, and inheritance patterns, we identified high-confidence variants in five brain-expressed miRNAs (targeting 326 genes) and 3' UTR miRNA target regions of 152 genes. Some genes, such as SCP2 and UCGC, were identified in multiple families. Using Gene Ontology overrepresentation analysis and protein-protein interaction network analysis, we identified clusters of genes and pathways that are important for neurodevelopment. The miRNAs and miRNA target genes identified in this study are potentially involved in neurodevelopmental disorders and should be considered for further functional studies.
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Affiliation(s)
- Anthony Wong
- Department of Genetics, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA; (A.W.); (A.Z.); (X.C.); (V.M.); (M.A.); (C.G.); (S.W.); (J.F.F.); (L.M.B.)
| | - Anbo Zhou
- Department of Genetics, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA; (A.W.); (A.Z.); (X.C.); (V.M.); (M.A.); (C.G.); (S.W.); (J.F.F.); (L.M.B.)
| | - Xiaolong Cao
- Department of Genetics, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA; (A.W.); (A.Z.); (X.C.); (V.M.); (M.A.); (C.G.); (S.W.); (J.F.F.); (L.M.B.)
| | - Vaidhyanathan Mahaganapathy
- Department of Genetics, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA; (A.W.); (A.Z.); (X.C.); (V.M.); (M.A.); (C.G.); (S.W.); (J.F.F.); (L.M.B.)
| | - Marco Azaro
- Department of Genetics, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA; (A.W.); (A.Z.); (X.C.); (V.M.); (M.A.); (C.G.); (S.W.); (J.F.F.); (L.M.B.)
| | - Christine Gwin
- Department of Genetics, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA; (A.W.); (A.Z.); (X.C.); (V.M.); (M.A.); (C.G.); (S.W.); (J.F.F.); (L.M.B.)
| | - Sherri Wilson
- Department of Genetics, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA; (A.W.); (A.Z.); (X.C.); (V.M.); (M.A.); (C.G.); (S.W.); (J.F.F.); (L.M.B.)
| | - Steven Buyske
- Department of Statistics, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA;
| | - Christopher W. Bartlett
- The Steve & Cindy Rasmussen Institute for Genomic Medicine, Battelle Center for Computational Biology, Abigail Wexner Research Institute at Nationwide Children’s Hospital, Columbus, OH 43215, USA;
- Department of Pediatrics, College of Medicine, The Ohio State University, Columbus, OH 43210, USA
| | - Judy F. Flax
- Department of Genetics, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA; (A.W.); (A.Z.); (X.C.); (V.M.); (M.A.); (C.G.); (S.W.); (J.F.F.); (L.M.B.)
| | - Linda M. Brzustowicz
- Department of Genetics, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA; (A.W.); (A.Z.); (X.C.); (V.M.); (M.A.); (C.G.); (S.W.); (J.F.F.); (L.M.B.)
- Human Genetics Institute of New Jersey, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
| | - Jinchuan Xing
- Department of Genetics, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA; (A.W.); (A.Z.); (X.C.); (V.M.); (M.A.); (C.G.); (S.W.); (J.F.F.); (L.M.B.)
- Human Genetics Institute of New Jersey, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
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3
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Tian C, Duan L, Fu C, He J, Dai J, Zhu G. Study on the Correlation Between Iris Characteristics and Schizophrenia. Neuropsychiatr Dis Treat 2022; 18:811-820. [PMID: 35431547 PMCID: PMC9005354 DOI: 10.2147/ndt.s361614] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 04/01/2022] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Recently, researchers have conducted many studies on the potential contribution of the retina and other eye structures on schizophrenia. This study aimed to evaluate differences in iris characteristics between patients with schizophrenia and healthy individuals so as to find more easily accessible and easily measurable biomarkers with a view to improving clinical assessments and furthering our understanding of the disease. METHODS Overall, 80 patients with schizophrenia and 52 healthy individuals were included in the case group and the control group, respectively. Iris images were collected from all subjects to compare differences in the structure and color of the iris. The Positive and Negative Symptom Scale (PANSS) and the Modified Overt Aggression Scale (MOAS) were used to evaluate the clinical symptoms and characteristics of 45 first-episode untreated schizophrenics, and analyzed correlations between iris characteristics and schizophrenia symptoms. RESULTS There were significant differences in iris crypts (P<0.05) and pigment spots (P<0.01) between the case and control group, but no significant difference was found in iris wrinkles (P<0.05). The logistic regression analysis demonstrated that the total iris crypts [odds ratio (OR) 1.166, 95% confidence interval (CI) 1.022-1.330] and total iris pigment spots (OR 1.815, 95% CI 1.186-2.775) increased the risk of suffering from schizophrenia. Furthermore, it was demonstrated that the number of iris crypts was positively associated with the MOAS score (r=0.474, P<0.01). Moreover, the number of the iris pigment spots (r=0.395, P<0.01) and wrinkles (r=0.309, P<0.05) were positively correlated with the subjects' negative symptom scores, respectively. CONCLUSION Iris crypts and pigment spots were identified as potential biomarkers for detecting schizophrenia. In patients with first-episode untreated schizophrenia, iris characteristics may help psychiatrists to identify the illness and its severity, and to detect characteristic clinical symptoms.
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Affiliation(s)
- Chunsheng Tian
- Department of Psychiatry, The First Affiliated Hospital of China Medical University, Shenyang, 110001, People's Republic of China.,Shenyang Mental Health Center, Shenyang, 110168, People's Republic of China
| | - Li Duan
- Department of Psychiatry, The First Affiliated Hospital of China Medical University, Shenyang, 110001, People's Republic of China.,School of Nursing, Chengde Medical University, Chengde, 067000, People's Republic of China
| | - Chunfeng Fu
- Department of Psychiatry, The First Affiliated Hospital of China Medical University, Shenyang, 110001, People's Republic of China
| | - Juan He
- Department of Psychiatry, The First Affiliated Hospital of China Medical University, Shenyang, 110001, People's Republic of China
| | - Jiali Dai
- Department of Psychiatry, The First Affiliated Hospital of China Medical University, Shenyang, 110001, People's Republic of China
| | - Gang Zhu
- Department of Psychiatry, The First Affiliated Hospital of China Medical University, Shenyang, 110001, People's Republic of China
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de Castro VF, Mattos D, de Carvalho FM, Cavalcanti DP, Duenas-Roque MM, Llerena J, Cosentino VR, Honjo RS, Leite JCL, Sanseverino MT, de Souza MPA, Bernardi P, Bolognese AM, Santana da Silva LC, Barbero P, Correia PS, Bueno LSM, Savastano CP, Orioli IM. New SHH and Known SIX3 Variants in a Series of Latin American Patients with Holoprosencephaly. Mol Syndromol 2021; 12:219-233. [PMID: 34421500 DOI: 10.1159/000515044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Accepted: 02/04/2021] [Indexed: 11/19/2022] Open
Abstract
Holoprosencephaly (HPE) is the failure of the embryonic forebrain to develop into 2 hemispheres promoting midline cerebral and facial defects. The wide phenotypic variability and causal heterogeneity make genetic counseling difficult. Heterozygous variants with incomplete penetrance and variable expressivity in the SHH, SIX3, ZIC2, and TGIF1 genes explain ∼25% of the known causes of nonchromosomal HPE. We studied these 4 genes and clinically described 27 Latin American families presenting with nonchromosomal HPE. Three new SHH variants and a third known SIX3 likely pathogenic variant found by Sanger sequencing explained 15% of our cases. Genotype-phenotype correlation in these 4 families and published families with identical or similar driver gene, mutated domain, conservation of residue in other species, and the type of variant explain the pathogenicity but not the phenotypic variability. Nine patients, including 2 with SHH pathogenic variants, presented benign variants of the SHH, SIX3, ZIC2, and TGIF1 genes with potential alteration of splicing, a causal proposition in need of further studies. Finding more families with the same SIX3 variant may allow further identification of genetic or environmental modifiers explaining its variable phenotypic expression.
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Affiliation(s)
- Viviane Freitas de Castro
- ECLAMC at Departamento de Genética, UFRJ, Rio de Janeiro, Brazil.,Instituto Nacional de Genética Médica Populacional INAGEMP, Porto Alegre, Brazil
| | - Daniel Mattos
- ECLAMC at Departamento de Genética, UFRJ, Rio de Janeiro, Brazil.,Instituto Nacional de Genética Médica Populacional INAGEMP, Porto Alegre, Brazil
| | - Flavia Martinez de Carvalho
- Instituto Nacional de Genética Médica Populacional INAGEMP, Porto Alegre, Brazil.,ECLAMC at Laboratorio Epidemiol. Malformações Congênitas, IOC/FIOCRUZ, Rio de Janeiro, Brazil
| | | | - Milagros M Duenas-Roque
- ECLAMC at Servicio de Genética, Hospital Nacional Edgardo Rebagliati Martins/EsSalud, Lima, Peru
| | - Juan Llerena
- Instituto Nacional de Genética Médica Populacional INAGEMP, Porto Alegre, Brazil.,ECLAMC at Centro de Genética Médica, IFF/FIOCRUZ, Rio de Janeiro, Brazil
| | | | | | | | | | | | - Pricila Bernardi
- Núcleo de Genética Clínica, Departamento de Clínica Médica/UFSC, Florianópolis, Brazil
| | - Ana Maria Bolognese
- Departamento de Ortodontia, Faculdade de Odontologia/UFRJ, Rio de Janeiro, Brazil
| | - Luiz Carlos Santana da Silva
- Instituto Nacional de Genética Médica Populacional INAGEMP, Porto Alegre, Brazil.,Laboratório de Erros Inatos de Metabolismo, Instituto de Ciências Biológicas/UFP, Belém, Brazil
| | - Pablo Barbero
- RENAC, Centro Nacional de Genética Médica Dr. Eduardo E. Castilla/MS, Buenos Aires, Argentina
| | | | | | | | - Iêda Maria Orioli
- ECLAMC at Departamento de Genética, UFRJ, Rio de Janeiro, Brazil.,Instituto Nacional de Genética Médica Populacional INAGEMP, Porto Alegre, Brazil
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5
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Gergics P, Smith C, Bando H, Jorge AAL, Rockstroh-Lippold D, Vishnopolska SA, Castinetti F, Maksutova M, Carvalho LRS, Hoppmann J, Martínez Mayer J, Albarel F, Braslavsky D, Keselman A, Bergadá I, Martí MA, Saveanu A, Barlier A, Abou Jamra R, Guo MH, Dauber A, Nakaguma M, Mendonca BB, Jayakody SN, Ozel AB, Fang Q, Ma Q, Li JZ, Brue T, Pérez Millán MI, Arnhold IJP, Pfaeffle R, Kitzman JO, Camper SA. High-throughput splicing assays identify missense and silent splice-disruptive POU1F1 variants underlying pituitary hormone deficiency. Am J Hum Genet 2021; 108:1526-1539. [PMID: 34270938 DOI: 10.1016/j.ajhg.2021.06.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Accepted: 06/18/2021] [Indexed: 12/13/2022] Open
Abstract
Pituitary hormone deficiency occurs in ∼1:4,000 live births. Approximately 3% of the cases are due to mutations in the alpha isoform of POU1F1, a pituitary-specific transcriptional activator. We found four separate heterozygous missense variants in unrelated individuals with hypopituitarism that were predicted to affect a minor isoform, POU1F1 beta, which can act as a transcriptional repressor. These variants retain repressor activity, but they shift splicing to favor the expression of the beta isoform, resulting in dominant-negative loss of function. Using a high-throughput splicing reporter assay, we tested 1,070 single-nucleotide variants in POU1F1. We identified 96 splice-disruptive variants, including 14 synonymous variants. In separate cohorts, we found two additional synonymous variants nominated by this screen that co-segregate with hypopituitarism. This study underlines the importance of evaluating the impact of variants on splicing and provides a catalog for interpretation of variants of unknown significance in POU1F1.
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Affiliation(s)
- Peter Gergics
- Department of Human Genetics, University of Michigan, Ann Arbor, MI 48109-5618, USA
| | - Cathy Smith
- Department of Human Genetics, University of Michigan, Ann Arbor, MI 48109-5618, USA; Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI 48109-2218, USA
| | - Hironori Bando
- Department of Human Genetics, University of Michigan, Ann Arbor, MI 48109-5618, USA
| | - Alexander A L Jorge
- Genetic Endocrinology Unit (LIM25), Division of Endocrinology, Hospital das Clinicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo 01246-903, Brazil
| | - Denise Rockstroh-Lippold
- Department of Women's and Child Health, Division of Pediatric Endocrinology, University Hospital Leipzig, Leipzig 04103, Germany
| | - Sebastian A Vishnopolska
- Instituto de Biociencias, Biotecnología y Biología Traslacional, Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad de Buenos Aires, CABA CE1428EHA, Argentina
| | - Frederic Castinetti
- Aix Marseille University, AP-HM, INSERM, Marseille Medical Genetics, Marmara Institute, La Conception Hospital, Department of Endocrinology, Marseille 13005, France
| | - Mariam Maksutova
- Department of Human Genetics, University of Michigan, Ann Arbor, MI 48109-5618, USA
| | - Luciani Renata Silveira Carvalho
- Developmental Endocrinology Unit, Laboratory of Hormones and Molecular Genetics LIM/42, Division of Endocrinology, Hospital das Clinicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo 05403-900, Brazil
| | - Julia Hoppmann
- Department of Women's and Child Health, Division of Pediatric Endocrinology, University Hospital Leipzig, Leipzig 04103, Germany
| | - Julián Martínez Mayer
- Instituto de Biociencias, Biotecnología y Biología Traslacional, Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad de Buenos Aires, CABA CE1428EHA, Argentina
| | - Frédérique Albarel
- Aix Marseille University, AP-HM, INSERM, Marseille Medical Genetics, Marmara Institute, La Conception Hospital, Department of Endocrinology, Marseille 13005, France
| | - Debora Braslavsky
- Centro de Investigaciones Endocrinológicas "Dr. César Bergadá," FEI - CONICET - División de Endocrinología, Hospital de Niños Ricardo Gutiérrez, Ciudad de Buenos Aires, CABA CE1428EHA, Argentina
| | - Ana Keselman
- Centro de Investigaciones Endocrinológicas "Dr. César Bergadá," FEI - CONICET - División de Endocrinología, Hospital de Niños Ricardo Gutiérrez, Ciudad de Buenos Aires, CABA CE1428EHA, Argentina
| | - Ignacio Bergadá
- Centro de Investigaciones Endocrinológicas "Dr. César Bergadá," FEI - CONICET - División de Endocrinología, Hospital de Niños Ricardo Gutiérrez, Ciudad de Buenos Aires, CABA CE1428EHA, Argentina
| | - Marcelo A Martí
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires e Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales CONICET, Pabellòn 2 de Ciudad Universitaria, Ciudad de Buenos Aires, CABA C1428EHA, Argentina
| | - Alexandru Saveanu
- Aix Marseille University, AP-HM, INSERM, Marseille Medical Genetics, Marmara Institute, La Conception Hospital, Laboratory of Molecular Biology, Marseille 13385, France
| | - Anne Barlier
- Aix Marseille University, AP-HM, INSERM, Marseille Medical Genetics, Marmara Institute, La Conception Hospital, Laboratory of Molecular Biology, Marseille 13385, France
| | - Rami Abou Jamra
- Institute of Human Genetics, University of Leipzig Medical Center, Leipzig 04103, Germany
| | - Michael H Guo
- Division of Endocrinology, Boston Children's Hospital and Department of Genetics, Harvard Medical School, Boston, MA 02115, USA
| | - Andrew Dauber
- Cincinnati Center for Growth Disorders, Division of Endocrinology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Marilena Nakaguma
- Developmental Endocrinology Unit, Laboratory of Hormones and Molecular Genetics LIM/42, Division of Endocrinology, Hospital das Clinicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo 05403-900, Brazil
| | - Berenice B Mendonca
- Developmental Endocrinology Unit, Laboratory of Hormones and Molecular Genetics LIM/42, Division of Endocrinology, Hospital das Clinicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo 05403-900, Brazil
| | - Sajini N Jayakody
- Department of Human Genetics, University of Michigan, Ann Arbor, MI 48109-5618, USA
| | - A Bilge Ozel
- Department of Human Genetics, University of Michigan, Ann Arbor, MI 48109-5618, USA
| | - Qing Fang
- Department of Human Genetics, University of Michigan, Ann Arbor, MI 48109-5618, USA
| | - Qianyi Ma
- Department of Human Genetics, University of Michigan, Ann Arbor, MI 48109-5618, USA
| | - Jun Z Li
- Department of Human Genetics, University of Michigan, Ann Arbor, MI 48109-5618, USA
| | - Thierry Brue
- Aix Marseille University, AP-HM, INSERM, Marseille Medical Genetics, Marmara Institute, La Conception Hospital, Department of Endocrinology, Marseille 13005, France
| | - María Ines Pérez Millán
- Instituto de Biociencias, Biotecnología y Biología Traslacional, Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad de Buenos Aires, CABA CE1428EHA, Argentina
| | - Ivo J P Arnhold
- Developmental Endocrinology Unit, Laboratory of Hormones and Molecular Genetics LIM/42, Division of Endocrinology, Hospital das Clinicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo 05403-900, Brazil
| | - Roland Pfaeffle
- Department of Women's and Child Health, Division of Pediatric Endocrinology, University Hospital Leipzig, Leipzig 04103, Germany; Institute of Human Genetics, University of Leipzig Medical Center, Leipzig 04103, Germany
| | - Jacob O Kitzman
- Department of Human Genetics, University of Michigan, Ann Arbor, MI 48109-5618, USA; Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI 48109-2218, USA.
| | - Sally A Camper
- Department of Human Genetics, University of Michigan, Ann Arbor, MI 48109-5618, USA.
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6
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Diaz C, Puelles L. Developmental Genes and Malformations in the Hypothalamus. Front Neuroanat 2020; 14:607111. [PMID: 33324176 PMCID: PMC7726113 DOI: 10.3389/fnana.2020.607111] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 10/26/2020] [Indexed: 12/15/2022] Open
Abstract
The hypothalamus is a heterogeneous rostral forebrain region that regulates physiological processes essential for survival, energy metabolism, and reproduction, mainly mediated by the pituitary gland. In the updated prosomeric model, the hypothalamus represents the rostralmost forebrain, composed of two segmental regions (terminal and peduncular hypothalamus), which extend respectively into the non-evaginated preoptic telencephalon and the evaginated pallio-subpallial telencephalon. Complex genetic cascades of transcription factors and signaling molecules rule their development. Alterations of some of these molecular mechanisms acting during forebrain development are associated with more or less severe hypothalamic and pituitary dysfunctions, which may be associated with brain malformations such as holoprosencephaly or septo-optic dysplasia. Studies on transgenic mice with mutated genes encoding critical transcription factors implicated in hypothalamic-pituitary development are contributing to understanding the high clinical complexity of these pathologies. In this review article, we will analyze first the complex molecular genoarchitecture of the hypothalamus resulting from the activity of previous morphogenetic signaling centers and secondly some malformations related to alterations in genes implicated in the development of the hypothalamus.
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Affiliation(s)
- Carmen Diaz
- Department of Medical Sciences, School of Medicine and Institute for Research in Neurological Disabilities, University of Castilla-La Mancha, Albacete, Spain
| | - Luis Puelles
- Department of Human Anatomy and Psychobiology and IMIB-Arrixaca Institute, University of Murcia, Murcia, Spain
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7
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Nagai-Tanima M, Hong S, Hu P, Carrington B, Sood R, Roessler E, Muenke M. Rare hypomorphic human variation in the heptahelical domain of SMO contributes to holoprosencephaly phenotypes. Hum Mutat 2020; 41:2105-2118. [PMID: 32906187 DOI: 10.1002/humu.24103] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Revised: 08/14/2020] [Accepted: 08/28/2020] [Indexed: 12/19/2022]
Abstract
Holoprosencephaly (HPE) is the most common congenital anomaly affecting the forebrain and face in humans and occurs as frequently as 1:250 conceptions or 1:10,000 livebirths. Sonic Hedgehog signaling molecule is one of the best characterized HPE genes that plays crucial roles in numerous developmental processes including midline neural patterning and craniofacial development. The Frizzled class G-protein coupled receptor Smoothened (SMO), whose signaling activity is tightly regulated, is the sole obligate transducer of Hedgehog-related signals. However, except for previous reports of somatic oncogenic driver mutations in human cancers (or mosaic tumors in rare syndromes), any potential disease-related role of SMO genetic variation in humans is largely unknown. To our knowledge, ours is the first report of a human hypomorphic variant revealed by functional testing of seven distinct nonsynonymous SMO variants derived from HPE molecular and clinical data. Here we describe several zebrafish bioassays developed and guided by a systems biology analysis. This analysis strategy, and detection of hypomorphic variation in human SMO, demonstrates the necessity of integrating the genomic variant findings in HPE probands with other components of the Hedgehog gene regulatory network in overall medical interpretations.
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Affiliation(s)
- Momoko Nagai-Tanima
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Sungkook Hong
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Ping Hu
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Blake Carrington
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA
- Zebrafish Core, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Raman Sood
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA
- Zebrafish Core, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Erich Roessler
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Maximilian Muenke
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA
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8
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Turcu DC, Lillehaug JR, Seo HC. SIX3 and SIX6 interact with GEMININ via C-terminal regions. Biochem Biophys Rep 2019; 20:100695. [PMID: 31844685 PMCID: PMC6895700 DOI: 10.1016/j.bbrep.2019.100695] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 10/09/2019] [Accepted: 10/10/2019] [Indexed: 01/13/2023] Open
Abstract
The histoarchitecture and function of eye and forebrain depend on a well-controlled balance between cell proliferation and differentiation. For example, the binding of the cell cycle regulator GEMININ to CDT1, which is a part of the pre-replication complex, promotes cell differentiation. Homeodomain transcription factors SIX3 and SIX6 also interact with GEMININ of which SIX3-GEMININ interaction promotes cell proliferation, whereas the nature of SIX6-GEMININ interaction has not been studied to date. We investigated SIX3/SIX6 and GEMININ interactions using bimolecular fluorescence complementation, surface plasmon resonance and isothermal titration calorimetry. Interactions between SIX3/SIX6 and GEMININ were detected in mammalian cells in culture. The presence of the C-terminal regions of SIX3 and SIX6 proteins, but not their SIX domains or homeodomains as previously thought, were required for interaction with GEMININ. Interestingly, the disordered C- and N- terminal regions of GEMININ were involved in binding to SIX3/SIX6. The coiled-coil region of GEMININ, which is the known protein-binding domain and also interacts with CDT1, was not involved in GEMININ-SIX3/SIX6 interaction. Using SPR and ITC, SIX3 bound GEMININ with a micromolar affinity and the binding stoichiometry was 1:2 (SIX3 - GEMININ). The present study gives new insights into the binding properties of SIX proteins, especially the role of their variable and disordered C-terminal regions.
C-terminal regions of SIX3/SIX6 bind GEMININ. GEMININ coiled-coil region is not involved in SIX3/SIX6 interaction. C- and N-terminal regions of GEMININ bind SIX3/SIX6. SIX3 binds GEMININ with a binding stoichiometry of 1:2.
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Affiliation(s)
- Diana C Turcu
- Department of Biological Sciences, University of Bergen, Bergen, Norway
| | - Johan R Lillehaug
- Department of Biological Sciences, University of Bergen, Bergen, Norway
| | - Hee-Chan Seo
- Department of Biological Sciences, University of Bergen, Bergen, Norway
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9
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Tatsi C, Xekouki P, Nioti O, Bachrach B, Belyavskaya E, Lyssikatos C, Stratakis CA. A novel mutation in the glucocorticoid receptor gene as a cause of severe glucocorticoid resistance complicated by hypertensive encephalopathy. J Hypertens 2019; 37:1475-1481. [PMID: 31145715 PMCID: PMC10913058 DOI: 10.1097/hjh.0000000000002048] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Glucocorticoid resistance syndrome (GRS) is caused by mutations of the glucocorticoid receptor (coded by the NR3C1 gene) and presents with signs of mineralocorticoid and/or androgen excess. PATIENT A female patient presented at the age of almost 3 years with hypertensive and hypoglycemic seizure. She was diagnosed with GRS and was treated with antihypertensive medications and dexamethasone. She was later found to have MRI findings of punctuate microinfarcts at the basal ganglia, left thalamus and pons, possibly associated with uncontrolled hypertension. Increase of the dexamethasone dose up to 14 mg/day resulted in sufficient control of her symptoms. RESULTS Two mutations in the NR3C1 gene were identified: a novel mutation in exon 2 (p.E198X), and a previously described mutation in exon 8 (p.R714Q). CONCLUSION GRS may present with life-threatening complications; this is the first report of hypertensive encephalopathy in association with GRS. Successful management of patients might require high doses of dexamethasone to control blood pressure.
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Affiliation(s)
- Christina Tatsi
- Section on Genetics and Endocrinology, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health, Bethesda, Maryland
| | - Paraskevi Xekouki
- Section on Genetics and Endocrinology, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health, Bethesda, Maryland
| | - Olga Nioti
- Section on Genetics and Endocrinology, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health, Bethesda, Maryland
| | - Bert Bachrach
- Pediatric Diabetes and Endocrinology Department, University of Missouri Children's Hospital, Columbia, Missouri, USA
| | - Elena Belyavskaya
- Section on Genetics and Endocrinology, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health, Bethesda, Maryland
| | - Charalampos Lyssikatos
- Section on Genetics and Endocrinology, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health, Bethesda, Maryland
| | - Constantine A Stratakis
- Section on Genetics and Endocrinology, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health, Bethesda, Maryland
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10
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Posbergh CJ, Thonney ML, Huson HJ. Genomic Approaches Identify Novel Gene Associations with Out of Season Lambing in Sheep. J Hered 2019; 110:577-586. [DOI: 10.1093/jhered/esz014] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Accepted: 02/27/2019] [Indexed: 12/20/2022] Open
Abstract
Abstract
Sheep are seasonally polyestrous, traditionally breeding when the day length shortens in the autumn. The changing photoperiod stimulates reproductive hormones through a series of chemical pathways, ultimately leading to cyclicity. Some breeds of sheep, such as the Polypay and Dorset, have been selected for reduced seasonality and can lamb year-round. Despite this selection, there is still variation within these breeds in the ability to lamb out of season. The identification of out of season lambing quantitative trait loci has the potential to improve genetic progress using genomic selection schemes. Association studies, fixation index (FST), and runs of homozygosity (ROH) were evaluated to identify regions of the genome that influence the ability of ewes to lamb out of season. All analyses used genotypic data from the Illumina Ovine HD beadchip. Genome-wide associations were tested both across breeds in 257 ewes and within the Dorset and Polypay breeds. FST was measured across breeds and between UK and US Dorsets to assess population differences. ROH were estimated in ewes to identify homozygous regions contributing to out of season lambing. Significant associations after multiple testing correction were found through these approaches, leading to the identification of several candidate genes for further study. Genes involved with eye development, reproductive hormones, and neuronal changes were identified as the most promising for influencing the ewe’s ability to lamb year-round. These candidate genes could be advantageous for selection for improved year-round lamb production and provide better insight into the complex regulation of seasonal reproduction.
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Affiliation(s)
| | | | - Heather J Huson
- Department of Animal Science, Cornell University, Ithaca, NY
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11
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Walter Costa MB, Höner zu Siederdissen C, Dunjić M, Stadler PF, Nowick K. SSS-test: a novel test for detecting positive selection on RNA secondary structure. BMC Bioinformatics 2019; 20:151. [PMID: 30898084 PMCID: PMC6429701 DOI: 10.1186/s12859-019-2711-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Accepted: 03/03/2019] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Long non-coding RNAs (lncRNAs) play an important role in regulating gene expression and are thus important for determining phenotypes. Most attempts to measure selection in lncRNAs have focused on the primary sequence. The majority of small RNAs and at least some parts of lncRNAs must fold into specific structures to perform their biological function. Comprehensive assessments of selection acting on RNAs therefore must also encompass structure. Selection pressures acting on the structure of non-coding genes can be detected within multiple sequence alignments. Approaches of this type, however, have so far focused on negative selection. Thus, a computational method for identifying ncRNAs under positive selection is needed. RESULTS We introduce the SSS-test (test for Selection on Secondary Structure) to identify positive selection and thus adaptive evolution. Benchmarks with biological as well as synthetic controls yield coherent signals for both negative and positive selection, demonstrating the functionality of the test. A survey of a lncRNA collection comprising 15,443 families resulted in 110 candidates that appear to be under positive selection in human. In 26 lncRNAs that have been associated with psychiatric disorders we identified local structures that have signs of positive selection in the human lineage. CONCLUSIONS It is feasible to assay positive selection acting on RNA secondary structures on a genome-wide scale. The detection of human-specific positive selection in lncRNAs associated with cognitive disorder provides a set of candidate genes for further experimental testing and may provide insights into the evolution of cognitive abilities in humans. AVAILABILITY The SSS-test and related software is available at: https://github.com/waltercostamb/SSS-test . The databases used in this work are available at: http://www.bioinf.uni-leipzig.de/Software/SSS-test/ .
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Affiliation(s)
- Maria Beatriz Walter Costa
- Embrapa Agroenergia, Parque Estação Biológica (PqEB), Asa Norte, Brasília, DF, 70770-901 Brazil
- Bioinformatics Group, Department of Computer Science, and Interdisciplinary Center for Bioinformatics, Universität Leipzig, Härtelstraße 16–18, Leipzig, 04107 Germany
| | - Christian Höner zu Siederdissen
- Bioinformatics Group, Department of Computer Science, and Interdisciplinary Center for Bioinformatics, Universität Leipzig, Härtelstraße 16–18, Leipzig, 04107 Germany
| | - Marko Dunjić
- Human Biology Group, Institute for Biology, Department of Biology, Chemistry, Pharmacy, Freie Universitaet Berlin, Königin-Luise-Straße 1-3, Berlin, 14195 Germany
- Center for Human Molecular Genetics, Faculty of Biology, University of Belgrade, Studentski trg 16, PO box 43, Belgrade, 11000 Serbia
| | - Peter F. Stadler
- Bioinformatics Group, Department of Computer Science, and Interdisciplinary Center for Bioinformatics, Universität Leipzig, Härtelstraße 16–18, Leipzig, 04107 Germany
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig & Competence Center for Scalable Data Services and Solutions Dresden-Leipzig & Leipzig Research Center for Civilization Diseases, University Leipzig, Leipzig, 04107 Germany
- Max Planck Institute for Mathematics in the Sciences, Inselstraße 22, Leipzig, 04103 Germany
- Department of Theoretical Chemistry, University of Vienna, Währinger Straße 17, Vienna, A-1090 Austria
- Center for non-coding RNA in Technology and Health, University of Copenhagen, Grønnegårdsvej 3, Frederiksberg C, DK-1870 Denmark
- Faculdad de Ciencias, Universidad Nacional de Colombia, Sede Bogotá, Ciudad Universitaria, Bogotá, D.C., COL-111321 Colombia
- Santa Fe Institute, 1399 Hyde Park Rd., Santa Fe, NM87501 USA
| | - Katja Nowick
- Human Biology Group, Institute for Biology, Department of Biology, Chemistry, Pharmacy, Freie Universitaet Berlin, Königin-Luise-Straße 1-3, Berlin, 14195 Germany
- TFome Research Group, Bioinformatics Group, Interdisciplinary Center of Bioinformatics, Department of Computer Science, University of Leipzig, Härtelstraße 16-18, Leipzig, 04107 Germany
- Paul-Flechsig-Institute for Brain Research, University of Leipzig, Liebigstraße 19. Haus C, Leipzig, 04103 Germany
- Bioinformatics, Faculty of Agricultural Sciences, Institute of Animal Science, University of Hohenheim, Garbenstraße 13, Stuttgart, 70593 Germany
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12
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Roessler E, Hu P, Marino J, Hong S, Hart R, Berger S, Martinez A, Abe Y, Kruszka P, Thomas JW, Mullikin JC, Wang Y, Wong WSW, Niederhuber JE, Solomon BD, Richieri-Costa A, Ribeiro-Bicudo LA, Muenke M. Common genetic causes of holoprosencephaly are limited to a small set of evolutionarily conserved driver genes of midline development coordinated by TGF-β, hedgehog, and FGF signaling. Hum Mutat 2018; 39:1416-1427. [PMID: 29992659 DOI: 10.1002/humu.23590] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Revised: 06/05/2018] [Accepted: 07/05/2018] [Indexed: 01/01/2023]
Abstract
Here, we applied targeted capture to examine 153 genes representative of all the major vertebrate developmental pathways among 333 probands to rank their relative significance as causes for holoprosencephaly (HPE). We now show that comparisons of variant transmission versus nontransmission among 136 HPE Trios indicates some reported genes now lack confirmation, while novel genes are implicated. Furthermore, we demonstrate that variation of modest intrinsic effect can synergize with these driver mutations as gene modifiers.
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Affiliation(s)
- Erich Roessler
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - Ping Hu
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | | | - Sungkook Hong
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - Rachel Hart
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - Seth Berger
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - Ariel Martinez
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - Yu Abe
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - Paul Kruszka
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - James W Thomas
- NIH Intramural Sequencing Center, NISC, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - James C Mullikin
- NIH Intramural Sequencing Center, NISC, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
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- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - Yupeng Wang
- Inova Translational Medicine Institute, Virginia Commonwealth University School of Medicine, Falls Church, Virginia
| | - Wendy S W Wong
- Inova Translational Medicine Institute, Virginia Commonwealth University School of Medicine, Falls Church, Virginia
| | - John E Niederhuber
- Inova Translational Medicine Institute, Virginia Commonwealth University School of Medicine, Falls Church, Virginia
| | - Benjamin D Solomon
- Inova Translational Medicine Institute, Virginia Commonwealth University School of Medicine, Falls Church, Virginia.,Presently the Managing Director, GeneDx, Gaithersburg, Maryland
| | - Antônio Richieri-Costa
- Hospital for the Rehabilitation of Craniofacial Anomalies, São Paulo University, São Paulo, Brazil
| | - L A Ribeiro-Bicudo
- Institute of Bioscience, Department of Genetics, Federal University of Goias, Goias, Brazil
| | - Maximilian Muenke
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
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13
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Roessler E, Hu P, Muenke M. Holoprosencephaly in the genomics era. AMERICAN JOURNAL OF MEDICAL GENETICS PART C-SEMINARS IN MEDICAL GENETICS 2018; 178:165-174. [PMID: 29770992 DOI: 10.1002/ajmg.c.31615] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Revised: 04/06/2018] [Accepted: 04/11/2018] [Indexed: 01/08/2023]
Abstract
Holoprosencephaly (HPE) is the direct consequence of specific genetic and/or environmental insults interrupting the midline specification of the nascent forebrain. Such disturbances can lead to a broad range of phenotypic consequences for the brain and face in humans. This malformation sequence is remarkably common in utero (1 in 250 human fetuses), but 97% typically do not survive to birth. The precise molecular pathogenesis of HPE in these early human embryos remains largely unknown. Here, we outline our current understanding of the principal driving factors leading to HPE pathologies and elaborate our multifactorial integrated genomics approach. Overall, our understanding of the pathogenesis continues to become simpler, rather than more complicated. Genomic technologies now provide unprecedented insight into disease-associated variation, including the overall extent of genetic interactions (coding and noncoding) predicted to explain divergent phenotypes.
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Affiliation(s)
- Erich Roessler
- Medical Genetics Branch, National Human, Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - Ping Hu
- Medical Genetics Branch, National Human, Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - Maximilian Muenke
- Medical Genetics Branch, National Human, Genome Research Institute, National Institutes of Health, Bethesda, Maryland
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14
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Stokes B, Berger SI, Hall BA, Weiss K, Hadley DW, Murdock DR, Ramanathan S, Clark RD, Roessler E, Kruszka P, Muenke M. SIX3 deletions and incomplete penetrance in families affected by holoprosencephaly. Congenit Anom (Kyoto) 2018; 58:29-32. [PMID: 28670735 PMCID: PMC5750110 DOI: 10.1111/cga.12234] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Revised: 05/09/2017] [Accepted: 06/25/2017] [Indexed: 12/27/2022]
Abstract
Holoprosencephaly (HPE) is failure of the forebrain to divide completely during embryogenesis. Incomplete penetrance has not been reported previously in SIX3 whole gene deletions, which are known to cause HPE. Both chromosomal microarray and whole exome sequencing (WES) were used to evaluate families with inherited HPE. Two families showed inherited deletions that contain SIX3 and were incompletely penetrant for HPE. Using WES, we ruled out parental mosaicism, a SIX3 hypomorph, and clinically significant variants in genes that are known to interact with SIX3 as causes of incomplete penetrance. We demonstrate the importance of molecular cascade testing in families with HPE and we answer important questions about incomplete penetrance.
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Affiliation(s)
- Bethany Stokes
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - Seth I. Berger
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - Beth A. Hall
- Minnesota Perinatal Physicians, Allina Health, Minneapolis Minnesota
| | - Karin Weiss
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - Donald W. Hadley
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - David R. Murdock
- Office of the Clinical Director, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - Subhadra Ramanathan
- Division of Medical Genetics, Department of Pediatrics, Loma Linda University Children's Hospital, Loma Linda, California
| | - Robin D. Clark
- Division of Medical Genetics, Department of Pediatrics, Loma Linda University Children's Hospital, Loma Linda, California
| | - Erich Roessler
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - Paul Kruszka
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - Maximilian Muenke
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
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15
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Ochi H, Kawaguchi A, Tanouchi M, Suzuki N, Kumada T, Iwata Y, Ogino H. Co-accumulation of cis-regulatory and coding mutations during the pseudogenization of the Xenopus laevis homoeologs six6.L and six6.S. Dev Biol 2017; 427:84-92. [PMID: 28501477 DOI: 10.1016/j.ydbio.2017.05.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Revised: 04/29/2017] [Accepted: 05/08/2017] [Indexed: 01/01/2023]
Abstract
Common models for the evolution of duplicated genes after genome duplication are subfunctionalization, neofunctionalization, and pseudogenization. Although the crucial roles of cis-regulatory mutations in subfunctionalization are well-documented, their involvement in pseudogenization and/or neofunctionalization remains unclear. We addressed this issue by investigating the evolution of duplicated homeobox genes, six6.L and six6.S, in the allotetraploid frog Xenopus laevis. Based on a comparative expression analysis, we observed similar eye-specific expression patterns for the two loci and their single ortholog in the ancestral-type diploid species Xenopus tropicalis. However, we detected lower levels of six6.S expression than six6.L expression. The six6.S enhancer sequence was more highly diverged from the orthologous enhancer of X. tropicalis than the six6.L enhancer, and showed weaker activity in a transgenic reporter assay. Based on a phylogenetic analysis of the protein sequences, we observed greater divergence between X. tropicalis Six6 and Six6.S than between X. tropicalis Six6 and Six6.L, and the observed mutations were reminiscent of a microphthalmia mutation in human SIX6. Misexpression experiments showed that six6.S has weaker eye-enlarging activity than six6.L, and targeted disruption of six6.L reduced the eye size more significantly than that of six6.S. These results suggest that enhancer attenuation stimulates the accumulation of hypomorphic coding mutations, or vice versa, in one duplicated gene copy and facilitates pseudogenization. We also underscore the value of the allotetraploid genome of X. laevis as a resource for studying latent pathogenic mutations.
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Affiliation(s)
- Haruki Ochi
- Faculty of Medicine, Yamagata University, 2-2-2 Iida-Nishi, Yamagata, Yamagata Prefecture 990-9585, Japan
| | - Akane Kawaguchi
- Department of Animal Bioscience, Nagahama Institute of Bio-Science and Technology, 1266 Tamura, Nagahama, Shiga 526-0829, Japan
| | - Mikio Tanouchi
- Amphibian Research Center, Hiroshima University, 1-3-1 Kagami-yama, Higashi-Hiroshima, Hiroshima 739-8526, Japan
| | - Nanoka Suzuki
- Faculty of Medicine, Yamagata University, 2-2-2 Iida-Nishi, Yamagata, Yamagata Prefecture 990-9585, Japan
| | - Tatsuki Kumada
- Faculty of Medicine, Yamagata University, 2-2-2 Iida-Nishi, Yamagata, Yamagata Prefecture 990-9585, Japan
| | - Yui Iwata
- Amphibian Research Center, Hiroshima University, 1-3-1 Kagami-yama, Higashi-Hiroshima, Hiroshima 739-8526, Japan
| | - Hajime Ogino
- Department of Animal Bioscience, Nagahama Institute of Bio-Science and Technology, 1266 Tamura, Nagahama, Shiga 526-0829, Japan; Amphibian Research Center, Hiroshima University, 1-3-1 Kagami-yama, Higashi-Hiroshima, Hiroshima 739-8526, Japan.
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16
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Paulussen ADC, Steyls A, Vanoevelen J, van Tienen FHJ, Krapels IPC, Claes GRF, Chocron S, Velter C, Tan-Sindhunata GM, Lundin C, Valenzuela I, Nagy B, Bache I, Maroun LL, Avela K, Brunner HG, Smeets HJM, Bakkers J, van den Wijngaard A. Rare novel variants in the ZIC3 gene cause X-linked heterotaxy. Eur J Hum Genet 2016; 24:1783-1791. [PMID: 27406248 PMCID: PMC5117940 DOI: 10.1038/ejhg.2016.91] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Revised: 04/25/2016] [Accepted: 05/20/2016] [Indexed: 02/08/2023] Open
Abstract
Variants in the ZIC3 gene are rare, but have demonstrated their profound clinical significance in X-linked heterotaxy, affecting in particular male patients with abnormal arrangement of thoracic and visceral organs. Several reports have shown relevance of ZIC3 gene variants in both familial and sporadic cases and with a predominance of mutations detected in zinc-finger domains. No studies so far have assessed the functional consequences of ZIC3 variants in an in vivo model organism. A study population of 348 patients collected over more than 10 years with a large variety of congenital heart disease including heterotaxy was screened for variants in the ZIC3 gene. Functional effects of three variants were assessed both in vitro and in vivo in the zebrafish. We identified six novel pathogenic variants (1,7%), all in either male patients with heterotaxy (n=5) or a female patient with multiple male deaths due to heterotaxy in the family (n=1). All variants were located within the zinc-finger domains or leading to a truncation before these domains. Truncating variants showed abnormal trafficking of mutated ZIC3 proteins, whereas the missense variant showed normal trafficking. Overexpression of wild-type and mutated ZIC protein in zebrafish showed full non-functionality of the two frame-shift variants and partial activity of the missense variant compared with wild-type, further underscoring the pathogenic character of these variants. Concluding, we greatly expanded the number of causative variants in ZIC3 and delineated the functional effects of three variants using in vitro and in vivo model systems.
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Affiliation(s)
- Aimee D C Paulussen
- Department of Clinical Genetics, Maastricht University Medical Center, Maastricht, The Netherlands
- School for Oncology and Developmental Biology (GROW), Maastricht University Medical Center, Maastricht, The Netherlands
| | - Anja Steyls
- Department of Clinical Genetics, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Jo Vanoevelen
- Department of Clinical Genetics, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Florence HJ van Tienen
- Department of Clinical Genetics, Maastricht University Medical Center, Maastricht, The Netherlands
- School for Oncology and Developmental Biology (GROW), Maastricht University Medical Center, Maastricht, The Netherlands
| | - Ingrid P C Krapels
- Department of Clinical Genetics, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Godelieve RF Claes
- Department of Clinical Genetics, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Sonja Chocron
- Cardiac Development and Genetics, Hubrecht Institute-KNAW and University Medical Centre Utrecht, The Netherlands
| | - Crool Velter
- Department of Clinical Genetics, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Gita M Tan-Sindhunata
- Department of Clinical Genetics, VU University Medical Center, Amsterdam, The Netherlands
| | - Catarina Lundin
- Department of Clinical Genetics, Office for Medical Services, Division of Laboratory Medicine, Lund, Sweden
| | - Irene Valenzuela
- Department of Clinical Genetics and Cytogenetics, Hospital Vall d'Hebron, Barcelona, Spain
| | - Balint Nagy
- Department of Obstetrics and Gynaecology, Semmelweis University, Budapest, Hungary
| | - Iben Bache
- Department of Clinical Genetics, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
- Wilhelm Johannsen Centre for Functional Genome Research, Department of Cellular and Molecular Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Lisa Leth Maroun
- Department of Pathology, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | | | - Han G Brunner
- Department of Clinical Genetics, Maastricht University Medical Center, Maastricht, The Netherlands
- Department of Human Genetics, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Hubert J M Smeets
- Department of Clinical Genetics, Maastricht University Medical Center, Maastricht, The Netherlands
- School for Oncology and Developmental Biology (GROW), Maastricht University Medical Center, Maastricht, The Netherlands
| | - Jeroen Bakkers
- Cardiac Development and Genetics, Hubrecht Institute-KNAW and University Medical Centre Utrecht, The Netherlands
| | - Arthur van den Wijngaard
- Department of Clinical Genetics, Maastricht University Medical Center, Maastricht, The Netherlands
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Gupta S, Sen J. Roof plate mediated morphogenesis of the forebrain: New players join the game. Dev Biol 2016; 413:145-52. [DOI: 10.1016/j.ydbio.2016.03.019] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Revised: 02/06/2016] [Accepted: 03/15/2016] [Indexed: 10/22/2022]
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18
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Beccari L, Marco-Ferreres R, Tabanera N, Manfredi A, Souren M, Wittbrodt B, Conte I, Wittbrodt J, Bovolenta P. A trans-Regulatory Code for the Forebrain Expression of Six3.2 in the Medaka Fish. J Biol Chem 2015; 290:26927-26942. [PMID: 26378230 PMCID: PMC4646366 DOI: 10.1074/jbc.m115.681254] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Revised: 09/11/2015] [Indexed: 12/16/2022] Open
Abstract
A well integrated and hierarchically organized gene regulatory network is responsible for the progressive specification of the forebrain. The transcription factor Six3 is one of the central components of this network. As such, Six3 regulates several components of the network, but its upstream regulators are still poorly characterized. Here we have systematically identified such regulators, taking advantage of the detailed functional characterization of the regulatory region of the medaka fish Six3.2 ortholog and of a time/cost-effective trans-regulatory screening, which complemented and overcame the limitations of in silico prediction approaches. The candidates resulting from this search were validated with dose-response luciferase assays and expression pattern criteria. Reconfirmed candidates with a matching expression pattern were also tested with chromatin immunoprecipitation and functional studies. Our results confirm the previously proposed direct regulation of Pax6 and further demonstrate that Msx2 and Pbx1 are bona fide direct regulators of early Six3.2 distribution in distinct domains of the medaka fish forebrain. They also point to other transcription factors, including Tcf3, as additional regulators of different spatial-temporal domains of Six3.2 expression. The activity of these regulators is discussed in the context of the gene regulatory network proposed for the specification of the forebrain.
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Affiliation(s)
- Leonardo Beccari
- Centro de Biología Molecular "Severo Ochoa," Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid, c/ Nicolas Cabrera 1, Madrid 28049, Spain,; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), c/ Nicolas Cabrera 1, Madrid 28049, Spain; Instituto Cajal, Consejo Superior de Investigaciones Científicas, Avda. Dr. Arce 37, Madrid, 28002, Spain,.
| | - Raquel Marco-Ferreres
- Centro de Biología Molecular "Severo Ochoa," Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid, c/ Nicolas Cabrera 1, Madrid 28049, Spain,; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), c/ Nicolas Cabrera 1, Madrid 28049, Spain; Instituto Cajal, Consejo Superior de Investigaciones Científicas, Avda. Dr. Arce 37, Madrid, 28002, Spain
| | - Noemi Tabanera
- Centro de Biología Molecular "Severo Ochoa," Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid, c/ Nicolas Cabrera 1, Madrid 28049, Spain,; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), c/ Nicolas Cabrera 1, Madrid 28049, Spain; Instituto Cajal, Consejo Superior de Investigaciones Científicas, Avda. Dr. Arce 37, Madrid, 28002, Spain
| | - Anna Manfredi
- Instituto Cajal, Consejo Superior de Investigaciones Científicas, Avda. Dr. Arce 37, Madrid, 28002, Spain
| | - Marcel Souren
- the Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany
| | - Beate Wittbrodt
- the Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany
| | - Ivan Conte
- Instituto Cajal, Consejo Superior de Investigaciones Científicas, Avda. Dr. Arce 37, Madrid, 28002, Spain,; the Telethon Institute of Genetics and Medicine, Via Campi Flegrei 34, Pozzuoli, Naples, 80078, Italy
| | - Jochen Wittbrodt
- the Centre for Organismal Studies, University of Heidelberg, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany
| | - Paola Bovolenta
- Centro de Biología Molecular "Severo Ochoa," Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid, c/ Nicolas Cabrera 1, Madrid 28049, Spain,; Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), c/ Nicolas Cabrera 1, Madrid 28049, Spain; Instituto Cajal, Consejo Superior de Investigaciones Científicas, Avda. Dr. Arce 37, Madrid, 28002, Spain,.
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Poelmans S, Kawamoto T, Cristofoli F, Politis C, Vermeesch J, Bailleul-Forestier I, Hens G, Devriendt K, Verdonck A, Carels C. Genotypic and phenotypic variation in six patients with solitary median maxillary central incisor syndrome. Am J Med Genet A 2015; 167A:2451-8. [PMID: 26080100 DOI: 10.1002/ajmg.a.37207] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Accepted: 06/03/2015] [Indexed: 11/09/2022]
Abstract
Solitary Median Maxillary Central Incisor occurs in 1 of 50,000 live births. It is the mildest manifestation of the holoprosencephaly spectrum and is genetically heterogeneous. Here we report six patients with solitary median maxillary central incisor, and a range of other phenotypic anomalies with different degrees of severity, varying from mild signs of holoprosencephaly to associated intellectual disability, and with different genetic background. Using array comparative genomic hybridization, pathogenic copy number variants were found in three of the six patients. Two patients had a deletion at the 18p11 chromosomal region that includes TGIF1 while the other patient had a deletion at 7q36, including the SHH gene. In one patient, a mutation in SIX3 was detected with exome sequencing, while in the two remaining patients all known holoprosencephaly genes were excluded using multiplex ligation-dependent probe amplification and sequencing, and remain unsolved. One of the two latter patients had isolated solitary median maxillary central incisor without other visible dentofacial anomalies, while the other had clinical features not part of the known holoprosencephaly spectrum.
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Affiliation(s)
- Simon Poelmans
- Department of Oral Health Sciences-Orthodontics, KU Leuven and Dentistry, University Hospitals Leuven, Leuven, Belgium
| | - Tatsuro Kawamoto
- Department of Orthodontics and Craniofacial Biology, College of Dentistry, Radboudumc, Nijmegen, The Netherlands
- Department of Maxillofacial Reconstruction and Function, Maxillofacial Orthognathics, Division of Maxillofacial/Neck Reconstruction, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan
| | - Francesca Cristofoli
- Department of Human Genetics, KU Leuven and Centre for Human Genetics, University Hospitals Leuven, Leuven, Belgium
| | - Constantinus Politis
- Department of Oral and Maxillofacial Surgery, KU Leuven and University Hospitals Leuven, Leuven, Belgium
| | - Joris Vermeesch
- Department of Human Genetics, KU Leuven and Centre for Human Genetics, University Hospitals Leuven, Leuven, Belgium
| | - Isabelle Bailleul-Forestier
- Department of Oral Health Sciences-Paediatric Dentistry and Special Care, KU Leuven and Dentistry, University Hospitals Leuven, Leuven, Belgium
- Department of Paediatric Dentistry, Paul Sabatier University, Hôpitaux de Toulouse, France
| | - Greet Hens
- Department of Otorhinolaryngology, Head and Neck Surgery, KU Leuven and University Hospitals Leuven, Leuven, Belgium
| | - Koenraad Devriendt
- Department of Human Genetics, KU Leuven and Centre for Human Genetics, University Hospitals Leuven, Leuven, Belgium
| | - Anna Verdonck
- Department of Oral Health Sciences-Orthodontics, KU Leuven and Dentistry, University Hospitals Leuven, Leuven, Belgium
| | - Carine Carels
- Department of Oral Health Sciences-Orthodontics, KU Leuven and Dentistry, University Hospitals Leuven, Leuven, Belgium
- Department of Orthodontics and Craniofacial Biology, College of Dentistry, Radboudumc, Nijmegen, The Netherlands
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20
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Santos-Ledo A, Cavodeassi F, Carreño H, Aijón J, Arévalo R. Ethanol alters gene expression and cell organization during optic vesicle evagination. Neuroscience 2013; 250:493-506. [PMID: 23892006 PMCID: PMC3988994 DOI: 10.1016/j.neuroscience.2013.07.036] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2012] [Revised: 06/25/2013] [Accepted: 07/10/2013] [Indexed: 01/12/2023]
Abstract
Ethanol alters eye morphogenesis at early stages of embryogenesis. The expression patterns of some genes important for eye morphogenesis are perturbed. Ethanol is related to alterations in cell morphology. Ethanol interferes with the optic vesicles evagination. Ethanol has been described as a teratogen in vertebrate development. During early stages of brain formation, ethanol affects the evagination of the optic vesicles, resulting in synophthalmia or cyclopia, phenotypes where the optic vesicles partially or totally fuse. The mechanisms by which ethanol affects the morphogenesis of the optic vesicles are however largely unknown. In this study we make use of in situ hybridization, electron microscopy and immunohistochemistry to show that ethanol has profound effects on cell organization and gene expression during the evagination of the optic vesicles. Exposure to ethanol during early eye development alters the expression patterns of some genes known to be important for eye morphogenesis, such as rx3/1 and six3a. Furthermore, exposure to ethanol interferes with the acquisition of neuroepithelial features by the eye field cells, which is clear at ultrastructual level. Indeed, ethanol disrupts the acquisition of fusiform cellular shapes within the eye field. In addition, tight junctions do not form and retinal progenitors do not properly polarize, as suggested by the mis-localization and down-regulation of zo1. We also show that the ethanol-induced cyclopic phenotype is significantly different to that observed in cyclopic mutants, suggesting a complex effect of ethanol on a variety of targets. Our results show that ethanol not only disrupts the expression pattern of genes involved in retinal morphogenesis, such as rx3 and rx1, but also disrupts the changes in cell polarity that normally occur during eye field splitting. Thus, ethylic teratology seems to be related not only to modifications in gene expression and cell death but also to alterations in cell morphology.
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Affiliation(s)
- A Santos-Ledo
- Departamento de Biología Celular y Patología, IBSAL-Instituto de Neurociencias de Castilla y León, Universidad de Salamanca, Spain
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21
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Gestri G, Link BA, Neuhauss SCF. The visual system of zebrafish and its use to model human ocular diseases. Dev Neurobiol 2012; 72:302-27. [PMID: 21595048 DOI: 10.1002/dneu.20919] [Citation(s) in RCA: 125] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Free swimming zebrafish larvae depend mainly on their sense of vision to evade predation and to catch prey. Hence, there is strong selective pressure on the fast maturation of visual function and indeed the visual system already supports a number of visually driven behaviors in the newly hatched larvae.The ability to exploit the genetic and embryonic accessibility of the zebrafish in combination with a behavioral assessment of visual system function has made the zebrafish a popular model to study vision and its diseases.Here, we review the anatomy, physiology, and development of the zebrafish eye as the basis to relate the contributions of the zebrafish to our understanding of human ocular diseases.
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Affiliation(s)
- Gaia Gestri
- Department of Cell and Developmental Biology, University College, London,UK.
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22
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Carlin D, Sepich D, Grover VK, Cooper MK, Solnica-Krezel L, Inbal A. Six3 cooperates with Hedgehog signaling to specify ventral telencephalon by promoting early expression of Foxg1a and repressing Wnt signaling. Development 2012; 139:2614-24. [PMID: 22736245 PMCID: PMC3383232 DOI: 10.1242/dev.076018] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/01/2012] [Indexed: 01/18/2023]
Abstract
Six3 exerts multiple functions in the development of anterior neural tissue of vertebrate embryos. Whereas complete loss of Six3 function in the mouse results in failure of forebrain formation, its hypomorphic mutations in human and mouse can promote holoprosencephaly (HPE), a forebrain malformation that results, at least in part, from abnormal telencephalon development. However, the roles of Six3 in telencephalon patterning and differentiation are not well understood. To address the role of Six3 in telencephalon development, we analyzed zebrafish embryos deficient in two out of three Six3-related genes, six3b and six7, representing a partial loss of Six3 function. We found that telencephalon forms in six3b;six7-deficient embryos; however, ventral telencephalic domains are smaller and dorsal domains are larger. Decreased cell proliferation or excess apoptosis cannot account for the ventral deficiency. Instead, six3b and six7 are required during early segmentation for specification of ventral progenitors, similar to the role of Hedgehog (Hh) signaling in telencephalon development. Unlike in mice, we observe that Hh signaling is not disrupted in embryos with reduced Six3 function. Furthermore, six3b overexpression is sufficient to compensate for loss of Hh signaling in isl1- but not nkx2.1b-positive cells, suggesting a novel Hh-independent role for Six3 in telencephalon patterning. We further find that Six3 promotes ventral telencephalic fates through transient regulation of foxg1a expression and repression of the Wnt/β-catenin pathway.
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Affiliation(s)
- Dan Carlin
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37232, USA
- Department of Developmental Biology, Washington University School of Medicine, St Louis, MO 63110, USA
| | - Diane Sepich
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37232, USA
- Department of Developmental Biology, Washington University School of Medicine, St Louis, MO 63110, USA
| | - Vandana K. Grover
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Michael K. Cooper
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Lilianna Solnica-Krezel
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37232, USA
- Department of Developmental Biology, Washington University School of Medicine, St Louis, MO 63110, USA
| | - Adi Inbal
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37232, USA
- Department of Medical Neurobiology, IMRIC, The Hebrew University-Hadassah Medical School, Jerusalem 91120, Israel
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23
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Roessler E, Vélez JI, Zhou N, Muenke M. Utilizing prospective sequence analysis of SHH, ZIC2, SIX3 and TGIF in holoprosencephaly probands to describe the parameters limiting the observed frequency of mutant gene×gene interactions. Mol Genet Metab 2012; 105:658-64. [PMID: 22310223 PMCID: PMC3309119 DOI: 10.1016/j.ymgme.2012.01.005] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2011] [Revised: 01/05/2012] [Accepted: 01/05/2012] [Indexed: 11/29/2022]
Abstract
Clinical molecular diagnostic centers routinely screen SHH, ZIC2, SIX3 and TGIF for mutations that can help to explain holoprosencephaly and related brain malformations. Here we report a prospective Sanger sequence analysis of 189 unrelated probands referred to our diagnostic lab for genetic testing. We identified 28 novel unique mutations in this group (15%) and no instances of deleterious mutations in two genes in the same subject. Our result extends that of other diagnostic centers and suggests that among the aggregate 475 prospectively sequenced holoprosencephaly probands there is negligible evidence for direct gene-gene interactions among these tested genes. We model the predictions of the observed mutation frequency in the context of the hypothesis that gene×gene interactions are a prerequisite for forebrain malformations, i.e. the "multiple-hit" hypothesis. We conclude that such a direct interaction would be expected to be rare and that more subtle genetic and environmental interactions are a better explanation for the clinically observed inter- and intra-familial variability.
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Affiliation(s)
- Erich Roessler
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Jorge I. Vélez
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Nan Zhou
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Maximilian Muenke
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
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24
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Morris AC. The genetics of ocular disorders: insights from the zebrafish. ACTA ACUST UNITED AC 2012; 93:215-28. [PMID: 21932431 DOI: 10.1002/bdrc.20211] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Proper formation of the vertebrate eye requires a precisely coordinated sequence of morphogenetic events that integrate the developmental contributions of the skin ectoderm, neuroectoderm, and head mesenchyme. Disruptions in this process result in ocular malformations or retinal degeneration and can cause significant visual impairment. The zebrafish is an excellent vertebrate model for the study of eye development and disease due to the transparency of the embryo, its ex utero development, and its amenability to forward genetic screens. This review will present an overview of the genetic methodologies utilized in the zebrafish, a description of several zebrafish models of congenital ocular diseases, and a discussion of the utility of the zebrafish for assessing the pathogenicity of candidate disease alleles.
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Affiliation(s)
- Ann C Morris
- Department of Biology, University of Kentucky, Lexington, USA.
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25
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Basel-Vanagaite L, Sprecher E, Gat A, Merlob P, Albin-Kaplanski A, Konen O, Solomon BD, Muenke M, Grzeschik KH, Sirota L. New syndrome of congenital circumferential skin folds associated with multiple congenital anomalies. Pediatr Dermatol 2012; 29:89-95. [PMID: 21995818 PMCID: PMC4131925 DOI: 10.1111/j.1525-1470.2011.01403.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Congenital circumferential skin folds can be found in individuals with no additional defects, as well as in patients with multiple congenital anomalies and developmental abnormalities. Current data point to etiological heterogeneity of syndromic cases. We describe a 7-month-old girl with a novel combination of symmetrical congenital circumferential skin folds, dysmorphic features, and multiple congenital abnormalities. Examination of the patient revealed symmetrical congenital circumferential skin folds and dysmorphic features, as well as multiple congenital anomalies including nasal pyriform aperture stenosis, ventricular septal defect, absent spleen, camptodactyly, and severe psychomotor retardation. Skin biopsy demonstrated subcutaneous fat extending into the superficial and deep reticular dermis. Sequencing of the CDON, SHH, ZIC2, SIX3, and TGIF genes (associated with holoprosencephaly) did not disclose pathogenic alterations. Extensive review of previously described cases of syndromic congenital circumferential skin folds did not reveal a similar combination of clinical and histopathological findings.
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Affiliation(s)
- Lina Basel-Vanagaite
- Schneider Children's Medical Center of Israel and Raphael Recanati Genetic Institute, Rabin Medical Center, Beilinson Campus, Petah Tikva, Israel.
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26
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Raam MS, Solomon BD, Muenke M. Holoprosencephaly: a guide to diagnosis and clinical management. Indian Pediatr 2011; 48:457-66. [PMID: 21743112 DOI: 10.1007/s13312-011-0078-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
CONTEXT Holoprosencephaly affects 1 in 8,000 live births and is the most common structural anomaly of the developing forebrain, resulting in facial dysmorphism, neurologic impairment, and additional clinical sequelae. Given the increasing relative contribution of genetic diseases to perinatal morbidity and mortality in India, proper recognition and management of holoprosencephaly can improve care for a significant number of affected Indian children. EVIDENCE ACQUISITION We used the PubMed database (search terms: "holoprosencephaly," "HPE," "holoprosencephaly India") and cross-referenced articles regarding holoprosencephaly, using our research group's extensive experience as a guide for identifying seminal papers in the field. RESULTS Holoprosencephaly is classified into four types based on the nature of the brain malformations as seen on neuroimaging and/or pathologic examination, with typically recognizable craniofacial phenotypes. Despite the identification of several genetic loci and other etiologic agents involved in pathogenesis, additional causes are elusive. Moreover, satisfactory explanations for phenomena such as incomplete penetrance and variable expressivity are lacking. CONCLUSIONS For each patient, pediatricians should follow a diagnostic protocol including dysmorphology examination, complete family history and ascertainment of risk factors, and neuroimaging. Many medical issues, including hypothalamic dysfunction, endocrinologic dysfunction, motor impairment, respiratory issues, seizures, and hydrocephalus should be prioritized in management. Pediatricians should work with genetic specialists to identify syndromic forms and to perform cytogenetic investigation, molecular screening, and genetic counseling in order to fully characterize prognosis and recurrence risk.
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Affiliation(s)
- Manu S Raam
- HHMI-NIH Research Scholars Program, Howard Hughes Medical Institute, Chevy Chase, MD, United States
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27
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Pineda-Alvarez DE, Solomon BD, Roessler E, Balog JZ, Hadley DW, Zein WM, Hadsall CK, Brooks BP, Muenke M. A broad range of ophthalmologic anomalies is part of the holoprosencephaly spectrum. Am J Med Genet A 2011; 155A:2713-20. [PMID: 21976454 PMCID: PMC3200498 DOI: 10.1002/ajmg.a.34261] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2011] [Accepted: 07/17/2011] [Indexed: 01/15/2023]
Abstract
Holoprosencephaly (HPE) is the most common disorder of the developing forebrain in humans, and is characterized by failed or incomplete cleavage of the cerebral hemispheres and deep brain structures. HPE includes wide phenotypic variability, with a continuum of both brain and craniofacial anomalies. While "classic" eye findings, including the spectrum of midline anomalies ranging from cyclopia to hypotelorism, as well as chorioretinal coloboma and microphthalmia, have been frequently described in patients with HPE, other subtle eye anomalies may also occur. In our study we prospectively analyzed a small cohort of 10 patients in whom we identified mutations in SHH, SIX3, ZIC2, or FGF8, the latter of which is a very recently described HPE-associated gene. We found that 9 of 10 patients had at least two ophthalmologic anomalies, including refractive errors, microcornea, microphthalmia, blepharoptosis, exotropia, and uveal coloboma. These findings contribute to the understanding of the phenotypic variability of the HPE spectrum, and highlight findings in one medically important but often incompletely investigated system.
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Affiliation(s)
- Daniel E. Pineda-Alvarez
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Benjamin D. Solomon
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Erich Roessler
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Joan Z. Balog
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Donald W. Hadley
- Social and Behavioral Research Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Wadih M. Zein
- National Eye Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Casey K. Hadsall
- National Eye Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Brian P. Brooks
- National Eye Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Maximilian Muenke
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA
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28
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Bosoi CM, Capra V, Allache R, Trinh VQH, De Marco P, Merello E, Drapeau P, Bassuk AG, Kibar Z. Identification and characterization of novel rare mutations in the planar cell polarity gene PRICKLE1 in human neural tube defects. Hum Mutat 2011; 32:1371-5. [PMID: 21901791 DOI: 10.1002/humu.21589] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2011] [Accepted: 07/23/2011] [Indexed: 01/08/2023]
Abstract
The planar cell polarity (PCP) pathway controls the process of convergent extension (CE) during gastrulation and neural tube closure, and has been implicated in the pathogenesis of neural tube defects (NTDs) in animal models and human cohorts. In this study, we analyzed the role of one core PCP gene PRICKLE1 in these malformations. We screened this gene in 810 unrelated NTD patients and identified seven rare missense heterozygous mutations that were absent in all controls analyzed and predicted to be functionally deleterious using bioinformatics. Functional validation of five PRICKLE1 variants in a zebrafish model demonstrated that one variant, p.Arg682Cys, antagonized the CE phenotype induced by the wild-type zebrafish prickle1a (zpk1a) in a dominant fashion. Our study demonstrates that PRICKLE1 could act as a predisposing factor to human NTDs and further expands our knowledge of the role of PCP genes in the pathogenesis of these malformations.
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Affiliation(s)
- Ciprian M Bosoi
- Department of Obstetrics and Gynecology, CHU Sainte Justine Research Center and University of Montreal, Montreal, Canada
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29
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Pineda-Alvarez DE, Roessler E, Hu P, Srivastava K, Solomon BD, Siple CE, Fan CM, Muenke M. Missense substitutions in the GAS1 protein present in holoprosencephaly patients reduce the affinity for its ligand, SHH. Hum Genet 2011; 131:301-10. [PMID: 21842183 DOI: 10.1007/s00439-011-1078-6] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2011] [Accepted: 08/02/2011] [Indexed: 10/17/2022]
Abstract
Holprosencephaly (HPE) is the most common disorder of the developing forebrain in humans, and is characterized by varying degrees of abnormal union of the cerebral hemispheres. These defects are typically co-associated with midline craniofacial anomalies. The combination of forebrain and craniofacial defects that comprise HPE can present along a broad and variable phenotypic spectrum. Both the SHH and NODAL signaling pathways play important roles in the pathogenesis of this disorder. Disruption of these pathways by chromosomal rearrangements, mutations in pathway-related genes and/or biochemical alterations are proposed to contribute to HPE in a large number of patients. Additional factors that are not yet fully delineated are also very likely to be involved in the pathogenesis and phenotypic heterogeneity of the disorder. Genetic loss of GAS1, a cell membrane receptor and positive regulator of SHH, has been demonstrated to contribute to the HPE phenotypic spectrum in animal models. We have evaluated the coding and flanking sequence of GAS1 in 394 patients who have clinical findings within the HPE phenotypic spectrum, and now report five novel missense sequence variants among five unrelated HPE probands. Finally, we tested the effect of these variants (as well as previously reported GAS1 variants) on the ability of GAS1 to bind to SHH. Here, we demonstrate that sequence variants in GAS1 can impair its physical interaction with SHH, suggesting a decrease in the SHH downstream signaling cascade as a pathogenic mechanism of disease.
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Affiliation(s)
- Daniel E Pineda-Alvarez
- Medical Genetics Branch, National Human Genome Research Institute (NHGRI), National Institutes of Health, Bethesda, MD 20892-3717, USA
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30
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Wannasilp N, Solomon BD, Warren-Mora N, Clegg NJ, Delgado MR, Lacbawan F, Hu P, Winder TL, Roessler E, Muenke M. Holoprosencephaly in a family segregating novel variants in ZIC2 and GLI2. Am J Med Genet A 2011; 155A:860-4. [PMID: 21416594 DOI: 10.1002/ajmg.a.33903] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2010] [Accepted: 12/23/2010] [Indexed: 02/03/2023]
Abstract
Holoprosencephaly (HPE) is the most common malformation of the human forebrain. Typical manifestations in affected patients include a characteristic pattern of structural brain and craniofacial anomalies. HPE may be caused by mutations in over 10 identified genes; the inheritance is traditionally viewed as autosomal dominant with highly variable expressivity and incomplete penetrance. We present the description of a family simultaneously segregating two novel variants in the HPE-associated genes, ZIC2 and GLI2, as well as the results of extensive population-based studies of the variant region in GLI2. This is the first time that multiple HPE-associated variants in these genes have been reported in one family, and raises important questions about how clinicians and researchers should view the inheritance of conditions such as HPE.
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Affiliation(s)
- Nilrat Wannasilp
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA
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Zhang W, Hong M, Bae GU, Kang JS, Krauss RS. Boc modifies the holoprosencephaly spectrum of Cdo mutant mice. Dis Model Mech 2010; 4:368-80. [PMID: 21183473 PMCID: PMC3097458 DOI: 10.1242/dmm.005744] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Holoprosencephaly (HPE) is caused by a failure to form the midline of the forebrain and/or midface. It is one of the most common human birth defects, but clinical expression is extremely variable. HPE is associated with mutations in the sonic hedgehog (SHH) pathway. Mice lacking the Shh pathway regulator Cdo (also called Cdon) display HPE with strain-dependent penetrance and expressivity, implicating silent modifier genes as one cause of the variability. However, the identities of potential HPE modifiers of this type are unknown. We report here that whereas mice lacking the Cdo paralog Boc do not have HPE, Cdo;Boc double mutants on a largely Cdo-resistant genetic background have lobar HPE with strong craniofacial anomalies and defects in Shh target gene expression in the developing forebrain. Boc is therefore a silent HPE modifier gene in mice. Furthermore, Cdo and Boc have specific, selective roles in Shh signaling in mammals, because Cdo;Boc double-mutant mice do not display the most severe HPE phenotype seen in Shh-null mice, nor do they have major defects in digit patterning or development of vertebrae, which are also Shh-dependent processes. This is in contrast to reported observations in Drosophila, where genetic removal of the Cdo and Boc orthologs Ihog and Boi results in a complete loss of response to the hedgehog ligand. Therefore, there is evolutionary divergence between mammals and insects in the requirement of the hedgehog pathway for Cdo/Ihog family members, with mammalian development involving additional factors and/or distinct mechanisms at this level of pathway regulation.
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Affiliation(s)
- Wei Zhang
- Department of Developmental and Regenerative Biology, Mount Sinai School of Medicine, New York, NY 10029, USA
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Abstract
PURPOSE OF REVIEW This review presents recent advances in our understanding and clinical management of holoprosencephaly (HPE). HPE is the most common developmental disorder of the human forebrain and involves incomplete or failed separation of the cerebral hemispheres. The epidemiology, clinical features, causes, diagnostic approach, management, and outcomes of HPE are discussed. RECENT FINDINGS Chromosomal abnormalities account for the most commonly identified cause of HPE. However, there are often unidentifiable causes in patients with nonsyndromic, nonchromosomal forms of HPE. The prevalence of HPE may be underestimated given that patients with mild forms often are not diagnosed until they present with severely affected children. Pregestational maternal diabetes mellitus is the most recognized risk factor for HPE, as supported by recent large-scale epidemiological studies. Genetic studies using microarray-based comparative genomic hybridization technology have resulted in better characterization of important HPE loci. SUMMARY HPE encompasses a wide spectrum of forebrain and midline defects, with an accompanying wide spectrum of clinical manifestations. A coordinated, multidisciplinary care team is required for clinical management of this complex disorder. Further research will enable us to better understand the pathogenesis and causes of HPE, and thus to improve the genetic counseling of patients and their families.
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Abstract
In vertebrate hedgehog signaling, hedgehog ligands are processed to become bilipidated and then multimerize, which allows them to leave the signaling cell via Dispatched 1 and become transported via glypicans and megalin to the responding cells. Hedgehog then interacts with a complex of Patched 1 and Cdo/Boc, which activates endocytic Smoothened to the cilium. Patched 1 regulates the activity of Smoothened (1) via Vitamin D3, which inhibits Smoothened in the absence of hedgehog ligand or (2) via oxysterols, which activate Smoothened in the presence of hedgehog ligand. Hedgehog ligands also interact with Hip1, Patched 2, and Gas1, which regulate the range as well as the level of hedgehog signaling. In vertebrates, Smoothened is shortened at its C-terminal end and lacks most of the phosphorylation sites of importance in Drosophila. Cos2, also of importance in Drosophila, plays no role in mammalian transduction, nor do its homologs Kif7 and Kif27. The cilium may provide a function analogous to that of Cos2 by linking Smoothened to the modulation of Gli transcription factors. Disorders associated with the hedgehog signaling network follow, including nevoid basal cell carcinoma syndrome, holoprosencephaly, Smith-Lemli-Opitz syndrome, Greig cephalopolysyndactyly syndrome, Pallister-Hall syndrome, Carpenter syndrome, and Rubinstein-Taybi syndrome.
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Affiliation(s)
- M Michael Cohen
- Department of Pediatrics, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada.
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Gongal PA, French CR, Waskiewicz AJ. Aberrant forebrain signaling during early development underlies the generation of holoprosencephaly and coloboma. Biochim Biophys Acta Mol Basis Dis 2010; 1812:390-401. [PMID: 20850526 DOI: 10.1016/j.bbadis.2010.09.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2009] [Accepted: 09/08/2010] [Indexed: 01/10/2023]
Abstract
In this review, we highlight recent literature concerning the signaling mechanisms underlying the development of two neural birth defects, holoprosencephaly and coloboma. Holoprosencephaly, the most common forebrain defect, occurs when the cerebral hemispheres fail to separate and is typically associated with mispatterning of embryonic midline tissue. Coloboma results when the choroid fissure in the eye fails to close. It is clear that Sonic hedgehog (Shh) signaling regulates both forebrain and eye development, with defects in Shh, or components of the Shh signaling cascade leading to the generation of both birth defects. In addition, other intercellular signaling pathways are known factors in the incidence of holoprosencephaly and coloboma. This review will outline recent advances in our understanding of forebrain and eye embryonic pattern formation, with a focus on zebrafish studies of Shh and retinoic acid pathways. Given the clear overlap in the mechanisms that generate both diseases, we propose that holoprosencephaly and coloboma can represent mild and severe aspects of single phenotypic spectrum resulting from aberrant forebrain development. This article is part of a Special Issue entitled Zebrafish Models of Neurological Diseases.
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Affiliation(s)
- Patricia A Gongal
- Department of Biological Sciences, University of Alberta, Edmonton, Canada
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Paulussen ADC, Schrander-Stumpel CT, Tserpelis DCJ, Spee MKM, Stegmann APA, Mancini GM, Brooks AS, Collée M, Maat-Kievit A, Simon MEH, van Bever Y, Stolte-Dijkstra I, Kerstjens-Frederikse WS, Herkert JC, van Essen AJ, Lichtenbelt KD, van Haeringen A, Kwee ML, Lachmeijer AMA, Tan-Sindhunata GMB, van Maarle MC, Arens YHJM, Smeets EEJGL, de Die-Smulders CE, Engelen JJM, Smeets HJ, Herbergs J. The unfolding clinical spectrum of holoprosencephaly due to mutations in SHH, ZIC2, SIX3 and TGIF genes. Eur J Hum Genet 2010; 18:999-1005. [PMID: 20531442 PMCID: PMC2987413 DOI: 10.1038/ejhg.2010.70] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2010] [Revised: 03/23/2010] [Accepted: 03/25/2010] [Indexed: 11/09/2022] Open
Abstract
Holoprosencephaly is a severe malformation of the brain characterized by abnormal formation and separation of the developing central nervous system. The prevalence is 1:250 during early embryogenesis, the live-born prevalence is 1:16 000. The etiology of HPE is extremely heterogeneous and can be teratogenic or genetic. We screened four known HPE genes in a Dutch cohort of 86 non-syndromic HPE index cases, including 53 family members. We detected 21 mutations (24.4%), 3 in SHH, 9 in ZIC2 and 9 in SIX3. Eight mutations involved amino-acid substitutions, 7 ins/del mutations, 1 frame-shift, 3 identical poly-alanine tract expansions and 2 gene deletions. Pathogenicity of mutations was presumed based on de novo character, predicted non-functionality of mutated proteins, segregation of mutations with affected family-members or combinations of these features. Two mutations were reported previously. SNP array confirmed detected deletions; one spanning the ZIC2/ZIC5 genes (approx. 100 kb) the other a 1.45 Mb deletion including SIX2/SIX3 genes. The mutation percentage (24%) is comparable with previous reports, but we detected significantly less mutations in SHH: 3.5 vs 10.7% (P=0.043) and significantly more in SIX3: 10.5 vs 4.3% (P=0.018). For TGIF1 and ZIC2 mutation the rate was in conformity with earlier reports. About half of the mutations were de novo, one was a germ line mosaic. The familial mutations displayed extensive heterogeneity in clinical manifestation. Of seven familial index patients only two parental carriers showed minor HPE signs, five were completely asymptomatic. Therefore, each novel mutation should be considered as a risk factor for clinically manifest HPE, with the caveat of reduced clinical penetrance.
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Affiliation(s)
- Aimée D C Paulussen
- Department of Clinical Genetics, School for Oncology & Developmental Biology (GROW), Maastricht UMC, The Netherlands.
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Chao CH, Wang HD, Yuh CH. Complexity of cis-regulatory organization of six3a during forebrain and eye development in zebrafish. BMC DEVELOPMENTAL BIOLOGY 2010; 10:35. [PMID: 20346166 PMCID: PMC2858731 DOI: 10.1186/1471-213x-10-35] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/13/2009] [Accepted: 03/26/2010] [Indexed: 11/10/2022]
Abstract
BACKGROUND Six3a belongs to the SIX family of homeodomain proteins and is expressed in the most anterior neural plate at the beginning of neurogenesis in various species. Though the function of Six3a as a crucial regulator of eye and forebrain development has been thoroughly investigated, the transcriptional regulation of six3a is not well understood. RESULTS To elucidate the transcriptional regulation of six3a, we performed an in vivo reporter assay. Alignment of the 21-kb region surrounding the zebrafish six3a gene with the analogous region from different species identified several conserved non-coding modules. Transgenesis in zebrafish identified two enhancer elements and one suppressor. The D module drives the GFP reporter in the forebrain and eyes at an early stage, while the A module is responsible for the later expression. The A module also works as a repressor suppressing ectopic expression from the D module. Mutational analysis further minimized the A module to four highly conserved elements and the D module to three elements. Using electrophoresis mobility shift assays, we also provided evidence for the presence of DNA-binding proteins in embryonic nuclear extracts. The transcription factors that may occupy those highly conserved elements were also predicted. CONCLUSION This study provides a comprehensive view of six3a transcription regulation during brain and eye development and offers an opportunity to establish the gene regulatory networks underlying neurogenesis in zebrafish.
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Affiliation(s)
- Chung-Hao Chao
- Division of Molecular and Genomic Medicine, National Health Research Institutes, Zhunan Town, Miaoli County, Taiwan
- College of Life Science and Institute of Biotechnology, National Tsing-Hua University, HsinChu, Taiwan
| | - Horng-Dar Wang
- College of Life Science and Institute of Biotechnology, National Tsing-Hua University, HsinChu, Taiwan
| | - Chiou-Hwa Yuh
- Division of Molecular and Genomic Medicine, National Health Research Institutes, Zhunan Town, Miaoli County, Taiwan
- College of Life Science and Institute of Bioinformatics and Structural Biology, National Tsing-Hua University, HsinChu, Taiwan
- Department of Biological Science & Technology, National Chiao Tung University, HsinChu, Taiwan
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Solomon BD, Mercier S, Vélez JI, Pineda-Alvarez DE, Wyllie A, Zhou N, Dubourg C, David V, Odent S, Roessler E, Muenke M. Analysis of genotype-phenotype correlations in human holoprosencephaly. AMERICAN JOURNAL OF MEDICAL GENETICS PART C-SEMINARS IN MEDICAL GENETICS 2010; 154C:133-41. [PMID: 20104608 DOI: 10.1002/ajmg.c.30240] [Citation(s) in RCA: 126] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Since the discovery of the first gene causing holoprosencephaly (HPE), over 500 patients with mutations in genes associated with non-chromosomal, non-syndromic HPE have been described, with detailed descriptions available in over 300. Comprehensive clinical analysis of these individuals allows examination for the presence of genotype-phenotype correlations. These correlations allow a degree of differentiation between patients with mutations in different HPE-associated genes and for the application of functional studies to determine intragenic correlations. These early correlations are an important advance in the understanding of the clinical aspects of this disease, and in general argue for continued analysis of the genetic and clinical findings of large cohorts of patients with rare diseases in order to better inform both basic biological insight and care and counseling for affected patients and families.
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Affiliation(s)
- Benjamin D Solomon
- National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA
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Roessler E, Muenke M. The molecular genetics of holoprosencephaly. AMERICAN JOURNAL OF MEDICAL GENETICS PART C-SEMINARS IN MEDICAL GENETICS 2010; 154C:52-61. [PMID: 20104595 DOI: 10.1002/ajmg.c.30236] [Citation(s) in RCA: 169] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Holoprosencephaly (HPE) has captivated the imagination of Man for millennia because its most extreme manifestation, the single-eyed cyclopic newborn infant, brings to mind the fantastical creature Cyclops from Greek mythology. Attempting to understand this common malformation of the forebrain in modern medical terms requires a systematic synthesis of genetic, cytogenetic, and environmental information typical for studies of a complex disorder. However, even with the advances in our understanding of HPE in recent years, there are significant obstacles remaining to fully understand its heterogeneity and extensive variability in phenotype. General lessons learned from HPE will likely be applicable to other malformation syndromes. Here we outline the common, and rare, genetic and environmental influences on this conserved developmental program of forebrain development and illustrate the similarities and differences between these malformations in humans and those of animal models.
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Affiliation(s)
- Erich Roessler
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892-3717, USA
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39
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Hehr U, Pineda-Alvarez DE, Uyanik G, Hu P, Zhou N, Hehr A, Schell-Apacik C, Altus C, Daumer-Haas C, Meiner A, Steuernagel P, Roessler E, Winkler J, Muenke M. Heterozygous mutations in SIX3 and SHH are associated with schizencephaly and further expand the clinical spectrum of holoprosencephaly. Hum Genet 2010; 127:555-61. [PMID: 20157829 PMCID: PMC4101187 DOI: 10.1007/s00439-010-0797-4] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2009] [Accepted: 01/28/2010] [Indexed: 11/28/2022]
Abstract
Schizencephaly (SCH) is a clinically and etiologically heterogeneous cerebral malformation presenting as unilateral or bilateral hemispheric cleft with direct connection between the inner and outer liquor spaces. The SCH cleft is usually lined by gray matter, which appears polymicrogyric implying an associated impairment of neuronal migration. The majority of SCH patients are sporadic, but familial SCH has been described. An initial report of heterozygous mutations in the homeobox gene EMX2 could not be confirmed in 52 patients investigated in this study in agreement with two independent SCH patient cohorts published previously. SCH frequently occurs with additional cerebral malformations like hypoplasia or aplasia of the septum pellucidum or optic nerve, suggesting the involvement of genes important for the establishment of midline forebrain structures. We therefore considered holoprosencephaly (HPE)-associated genes as potential SCH candidates and report for the first time heterozygous mutations in SIX3 and SHH in a total of three unrelated patients and one fetus with SCH; one of them without obvious associated malformations of midline forebrain structures. Three of these mutations have previously been reported in independent patients with HPE. SIX3 acts directly upstream of SHH, and the SHH pathway is a key regulator of ventral forebrain patterning. Our data indicate that in a subset of patients SCH may develop as one aspect of a more complex malformation of the ventral forebrain, directly result from mutations in the SHH pathway and hence be considered as yet another feature of the broad phenotypic spectrum of holoprosencephaly.
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Affiliation(s)
- Ute Hehr
- Center for Human Genetics, Franz-Josef-Strauss-Allee 11, Universitätsklinikum D3, 93053 Regensburg, Germany.
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Pineda-Alvarez DE, Dubourg C, David V, Roessler E, Muenke M. Current recommendations for the molecular evaluation of newly diagnosed holoprosencephaly patients. AMERICAN JOURNAL OF MEDICAL GENETICS. PART C, SEMINARS IN MEDICAL GENETICS 2010; 154C:93-101. [PMID: 20104604 PMCID: PMC2815008 DOI: 10.1002/ajmg.c.30253] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Holoprosencephaly (HPE) is the most common structural malformation of the developing forebrain in humans and is typically characterized by different degrees of hemispheric separation that are often accompanied by similarly variable degrees of craniofacial and midline anomalies. HPE is a classic example of a complex genetic trait with "pseudo"-autosomal dominant transmission showing incomplete penetrance and variable expressivity. Clinical suspicion of HPE is typically based upon compatible craniofacial findings, the presence of developmental delay or seizures, or specific endocrinological abnormalities, and is then followed up by confirmation with brain imaging. Once a clinical diagnosis is made, a thorough genetic evaluation is necessary. This usually includes analysis of chromosomes by high-resolution karyotyping, clinical assessment to rule-out well recognized syndromes that are associated with HPE (e.g., Pallister-Hall syndrome, Smith-Lemli-Opitz syndrome and others), and molecular studies of the most common HPE associated genes (e.g., SHH, ZIC2 and SIX3). In this review, we provide current step-by-step recommendations that are medically indicated for the genetic evaluation of patients with newly diagnosed HPE. Moreover, we provide a brief review of several available methods used in molecular diagnostics of HPE and describe the advantages and limitations of both currently available and future tests as they relate to high throughput screening, cost, and the results that they may provide.
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Affiliation(s)
| | - Christèle Dubourg
- Université de Rennes 1, Faculté de Médecine - UMR 6061 CNRS, IFR140 GFAS, Rennes, France
- CHU Pontchaillou - Laboratoire de Génétique Moléculaire, Rennes, France
| | - Véronique David
- Université de Rennes, 35042 - CNRS Génétique et Développement, Rennes, France
| | - Erich Roessler
- National Human Genome Research Institute - Medical Genetics Branch, Bethesda, Maryland, USA
| | - Maximilian Muenke
- National Human Genome Research Institute - Medical Genetics Branch, Bethesda, Maryland, USA
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41
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Roessler E, El-Jaick KB, Dubourg C, Vélez JI, Solomon BD, Pineda-Álvarez DE, Lacbawan F, Zhou N, Ouspenskaia M, Paulussen A, Smeets HJ, Hehr U, Bendavid C, Bale S, Odent S, David V, Muenke M. The mutational spectrum of holoprosencephaly-associated changes within the SHH gene in humans predicts loss-of-function through either key structural alterations of the ligand or its altered synthesis. Hum Mutat 2009; 30:E921-35. [PMID: 19603532 PMCID: PMC2772877 DOI: 10.1002/humu.21090] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Mutations within either the SHH gene or its related pathway components are the most common, and best understood, pathogenetic changes observed in holoprosencephaly patients; this fact is consistent with the essential functions of this gene during forebrain development and patterning. Here we summarize the nature and types of deleterious sequence alterations among over one hundred distinct mutations in the SHH gene (64 novel mutations) and compare these to over a dozen mutations in disease-related Hedgehog family members IHH and DHH. This combined structural analysis suggests that dysfunction of Hedgehog signaling in human forebrain development can occur through truncations or major structural changes to the signaling domain, SHH-N, as well as due to defects in the processing of the mature ligand from its pre-pro-precursor or defective post-translation bi-lipid modifications with palmitate and cholesterol.
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Affiliation(s)
- Erich Roessler
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Kenia B. El-Jaick
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Christèle Dubourg
- Laboratoire de Génétique Moléculaire, CHU Pontchaillou, Rennes Cedex, France
- CNRS UMR6061 Génétique et Développement, Université de Rennes 1, IFR140, France
| | - Jorge I. Vélez
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Benjamin D. Solomon
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Daniel E. Pineda-Álvarez
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Felicitas Lacbawan
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Nan Zhou
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Maia Ouspenskaia
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Aimée Paulussen
- Academic Hospital and Department of Clinical Genetics, University of Maastricht, the Netherlands
| | - Hubert J. Smeets
- Academic Hospital and Department of Clinical Genetics, University of Maastricht, the Netherlands
| | - Ute Hehr
- Center for Human Genetics and Department of Human Genetics, University of Regensburg, Germany
| | - Claude Bendavid
- Laboratoire de Génétique Moléculaire, CHU Pontchaillou, Rennes Cedex, France
- CNRS UMR6061 Génétique et Développement, Université de Rennes 1, IFR140, France
| | | | - Sylvie Odent
- CNRS UMR6061 Génétique et Développement, Université de Rennes 1, IFR140, France
- Service de génétique clinique,CHU Hôpital Sud, Rennes, France
| | - Véronique David
- Laboratoire de Génétique Moléculaire, CHU Pontchaillou, Rennes Cedex, France
- CNRS UMR6061 Génétique et Développement, Université de Rennes 1, IFR140, France
| | - Maximilian Muenke
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
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Lacbawan F, Solomon BD, Roessler E, El-Jaick K, Domené S, Vélez JI, Zhou N, Hadley D, Balog JZ, Long R, Fryer A, Smith W, Omar S, McLean SD, Clarkson K, Lichty A, Clegg NJ, Delgado MR, Levey E, Stashinko E, Potocki L, Vanallen MI, Clayton-Smith J, Donnai D, Bianchi DW, Juliusson PB, Njølstad PR, Brunner HG, Carey JC, Hehr U, Müsebeck J, Wieacker PF, Postra A, Hennekam RCM, van den Boogaard MJH, van Haeringen A, Paulussen A, Herbergs J, Schrander-Stumpel CTRM, Janecke AR, Chitayat D, Hahn J, McDonald-McGinn DM, Zackai EH, Dobyns WB, Muenke M. Clinical spectrum of SIX3-associated mutations in holoprosencephaly: correlation between genotype, phenotype and function. J Med Genet 2009; 46:389-98. [PMID: 19346217 PMCID: PMC3510661 DOI: 10.1136/jmg.2008.063818] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND Holoprosencephaly (HPE) is the most common structural malformation of the human forebrain. There are several important HPE mutational target genes, including the transcription factor SIX3, which encodes an early regulator of Shh, Wnt, Bmp and Nodal signalling expressed in the developing forebrain and eyes of all vertebrates. OBJECTIVE To characterise genetic and clinical findings in patients with SIX3 mutations. METHODS Patients with HPE and their family members were tested for mutations in HPE-associated genes and the genetic and clinical findings, including those for additional cases found in the literature, were analysed. The results were correlated with a mutation-specific functional assay in zebrafish. RESULTS In a cohort of patients (n = 800) with HPE, SIX3 mutations were found in 4.7% of probands and additional cases were found through testing of relatives. In total, 138 cases of HPE were identified, 59 of whom had not previously been clinically presented. Mutations in SIX3 result in more severe HPE than in other cases of non-chromosomal, non-syndromic HPE. An over-representation of severe HPE was found in patients whose mutations confer greater loss of function, as measured by the functional zebrafish assay. The gender ratio in this combined set of patients was 1.5:1 (F:M) and maternal inheritance was almost twice as common as paternal. About 14% of SIX3 mutations in probands occur de novo. There is a wide intrafamilial clinical range of features and classical penetrance is estimated to be at least 62%. CONCLUSIONS Our data suggest that SIX3 mutations result in relatively severe HPE and that there is a genotype-phenotype correlation, as shown by functional studies using animal models.
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Affiliation(s)
- F Lacbawan
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, 35 Convent Drive, MSC 3717, Building 35, Room 1B-203, Bethesda, MD 20892-3717, USA
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Abstract
Holoprosencephaly (HPE), the most common human forebrain malformation, occurs in 1 in 250 fetuses and 1 in 16,000 live births. HPE is etiologically heterogeneous, and its pathology is variable. Several mouse models of HPE have been generated, and some of the molecular causes of different forms of HPE and the mechanisms underlying its variable pathology have been revealed by these models. Herein, we summarize the current knowledge on the genetic alterations that cause HPE and discuss some important questions about this disease that remain to be answered.
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Affiliation(s)
- Xin Geng
- Department of Genetics and Tumor Cell Biology, St. Jude Children's Research Hospital, Memphis, Tennessee 38105, USA
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Solomon BD, Lacbawan F, Jain M, Domené S, Roessler E, Moore C, Dobyns WB, Muenke M. A novel SIX3 mutation segregates with holoprosencephaly in a large family. Am J Med Genet A 2009; 149A:919-25. [PMID: 19353631 PMCID: PMC2737713 DOI: 10.1002/ajmg.a.32813] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Holoprosencephaly is the most common structural malformation of the forebrain in humans and has a complex etiology including chromosomal aberrations, single gene mutations and environmental components. Here we present the pertinent clinical findings among members of an unusually large kindred ascertained over 15 years ago following the evaluation and subsequent genetic work-up of a female infant with congenital anomalies. A genome-wide scan and linkage analysis showed only suggestive evidence of linkage to markers on chromosome 2 among the most likely of several pedigree interpretations. We now report that a novel missense mutation in the SIX3 holoprosencephaly gene is the likely cause in this family. Molecular genetic analysis and/or clinical characterization now show that at least 15 members of this family are presumed SIX3 mutation gene carriers, with clinical manifestations ranging from phenotypically normal adults (non-penetrance) to alobar holoprosencephaly incompatible with postnatal life. This particular family represents a seminal example of the variable manifestations of gene mutations in holoprosencephaly and difficulties encountered in their elucidation.
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Affiliation(s)
- Benjamin D. Solomon
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - Felicitas Lacbawan
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
- Department of Pathology, State University of New York Downstate Medical Center, Brooklyn, New York
| | - Mahim Jain
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - Sabina Domené
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - Erich Roessler
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - Cynthia Moore
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, Indiana
| | - William B. Dobyns
- Departments of Human Genetics, Neurology, and Pediatrics, The University of Chicago, Chicago, Illinois
| | - Maximilian Muenke
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
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