Genome-wide association has identified regions of the genome that mediate risk for psychosis. It is possible that variants in these regions confer risk by altering gene expression. This work has predominantly been conducted in individuals of European descent and has focused narrowly on schizophrenia rather than psychosis as a syndrome. In the present study we investigated alterations in gene expression in African American individuals with a range of psychotic diagnoses to increase understanding of the etiology in an underserved population. We performed RNA-seq in whole bloody to survey the transcriptome in 126 patients with a psychosis-spectrum disorder and 217 healthy controls and applied differential gene expression analyses across the genome while controlling for age, sex, population stratification and batch. We found 18 differentially expressed genes (DEGs), some of the locations of the corresponding genes overlap with previously implicated regions for psychosis, but many of which were novel associations. Enrichment analysis of nominally significant genes (p < 0.05) revealed overrepresentation of biological processes relating to platelet, immune and cellular function, and sensory perception. Weighted gene co-expression network analysis, applied to identify modules of co-expressed genes associated with psychosis, revealed 10 modules, one of which was significantly associated with psychosis. This module was significantly enriched for DEGs, and for platelet function. These results support the potential role of immune function in the etiology of psychosis, identify novel candidate gene expression phenotypes that correspond to both established and new genomic regions, in individuals of African American ancestry.

Next-generation sequencing (NGS) has emerged as a pivotal technology in the field of oncology, transforming the approach to cancer diagnosis and treatment. This paper provides a comprehensive overview of the integration of NGS into clinical settings, emphasizing its significant contributions to precision medicine. NGS enables detailed genomic profiling of tumors, identifying genetic alterations that drive cancer progression and facilitating personalized treatment plans targeting specific mutations, thereby improving patient outcomes. This capability facilitates the development of personalized treatment plans targeting specific mutations, leading to improved patient outcomes and the potential for better prognosis. The application of NGS extends beyond identifying actionable mutations; it is instrumental in detecting hereditary cancer syndromes, thus aiding in early diagnosis and preventive strategies. Furthermore, NGS plays a crucial role in monitoring minimal residual disease, offering a sensitive method to detect cancer recurrence at an early stage. Its use in guiding immunotherapy by identifying biomarkers that predict response to treatment is also highlighted. Ethical issues related to genetic testing, such as concerns around patient consent and data privacy, are also important considerations that need to be addressed for the broader implementation of NGS. These include the complexities of data interpretation, the need for robust bioinformatics support, cost considerations, and ethical issues related to genetic testing. Addressing these challenges is essential for the widespread adoption of NGS. Looking forward, advancements such as single-cell sequencing and liquid biopsies promise to further enhance the precision of cancer diagnostics and treatment. This review emphasizes the transformative impact of NGS in oncology and advocates for its incorporation into routine clinical practice to promote molecularly driven cancer care.

To evaluate the role of parental magnetic resonance imaging (MRI) in assessing fetuses with suspected brain anomalies and its use in prenatal counselling.

A retrospective, multicentre chart review was conducted on fetuses who underwent brain MRI because of suspected brain abnormalities between January 2008 and December 2022, with one or both parents who underwent brain MRI (MRI-Trio) as part of prenatal counselling. Clinical and demographic data were collected, including fetal and parental MRI findings, prenatal counselling outcomes, genetic testing results, family and previous pregnancy history, neurological examinations of the born children up to 24 months of age, and autopsy reports of fetuses from terminated pregnancies. MRI-Trio concordance was defined as at least one abnormal brain feature identified with similarity in the fetus and the parents. The live-born children were assessed postnatally through either neurodevelopmental evaluations or telephone interviews.

Sixty pregnancies were included (41.7% with concordant and 58.3% with discordant MRI-Trio). Forty-two children were born (70%) and 17 pregnancies were terminated (28.3%). One case of in utero fetal death (1.7%) was reported. The most common brain findings were multiple anomalies (n = 26, 43.3%), isolated disorders of the corpus callosum (n = 17, 28.3%), atypical periventricular pseudocysts (n = 6, 10%), and anomalies of the anterior complex (n = 4, 6.7%). MRI-Trio enabled better prognostication. When MRI-Trio was concordant, counselling was more favourable (n = 22, 36.6%) and the majority of live-born children exhibited typical development (p < 0.001).

MRI-Trio is a valuable tool for identifying dominantly inherited brain anomalies that may not hold developmental significance or are associated with favourable outcomes, acknowledging the potential for variable penetrance, which may result in more severe presentations. Concordant MRI-Trio findings can enhance the accuracy of prenatal counselling, potentially reducing the incidence of termination of pregnancy.

The majority of patients undergoing exome or genome sequencing receive a nondiagnostic result. Periodic reanalysis is known to increase diagnostic yield from exome sequencing, yet laboratory reanalysis practices are obscure. We sought to define the landscape of exome and genome reanalysis across clinical laboratories. Genetic testing registries were queried to identify eligible clinical genetic laboratories offering exome and/or genome sequencing in the United States. A survey administered to lab representatives investigated reanalysis offerings, policies, perceived uptake, bioinformatic steps, and billing options. The analysis consisted of descriptive statistics. Survey data were collected from 30 of 32 eligible laboratories (93%), comprising 28 exome products and 13 genome products. Reanalysis was widely available for both exomes (n = 27/28, 96%) and genomes (n = 12/13, 92%). Most participating laboratories required ordering providers to initiate reanalysis (n = 24/28, 86%). Most respondents estimated providers initiated reanalysis in less than 10% of all exomes (n = 12/22) or genomes (n = 6/9) sequenced. The approach to reanalysis varied greatly by laboratory. Laboratory approaches to exome and genome reanalysis are highly variable and typically require provider initiation. This could contribute to low reanalysis uptake and increased administrative burden on providers. Further work should emphasize development of clinical exome and genome reanalysis standards.

The completion of the Human Genome Project in 2003 has led to significant advances in patient care in medicine, particularly in diagnosing and managing genetic diseases and cancer. In the realm of genetic diseases, approximately 15% of critically ill infants born in the U.S.A. are diagnosed with genetic disorders, which comprise a significant cause of mortality in neonatal and pediatric intensive care units. The introduction of rapid whole-genome sequencing (rWGS) as a first-tier test in critically ill children with suspected, undiagnosed genetic diseases is a breakthrough in the diagnosis and subsequent clinical management of such infants and older children in intensive care units. Rapid genome sequencing is currently being used clinically in the USA, the UK, the Netherlands, Sweden, and Australia, among other countries. This review is intended for students and clinical practitioners, including non-experts in genetics, for whom it provides a historical background and a chronological review of the relevant published literature for the progression of pediatric diagnostic genomic sequencing leading to the development of pediatric rWGS in critically ill infants and older children with suspected but undiagnosed genetic diseases. Factors that will help to develop rWGS as a clinical test in critically ill infants and the limitations are briefly discussed, including an evaluation of the clinical utility and accessibility of genetic testing, education for parents and providers, cost-effectiveness, ethical challenges, consent issues, secondary findings, data privacy concerns, false-positive and false-negative results, challenges in variant interpretation, costs and reimbursement, the limited availability of genetic counselors, and the development of evidence-based guidelines, which would all need to be addressed to facilitate the implementation of pediatric genomic sequencing in an effective widespread manner in the era of precision medicine.

Arrhythmogenic cardiomyopathy (ACM) is one of the leading causes of sudden cardiac death in children, young adults, and athletes and is characterized by the fibro-fatty replacement of the myocardium, predominantly of the right ventricle. Sixty percent of patients with ACM have a known genetic cause, but for the remainder, the pathogenesis is unknown. This lack of mechanistic understanding has slowed the development of disease-modifying therapies, and children with ACM have a high degree of morbidity and mortality.

Induced pluripotent stem cells (iPSCs) from 3 family members were differentiated into cardiac myocytes (CMs). Calcium imaging was conducted by labeling calcium with CAL-520 and confocal imaging to capture calcium sparks after iPSC-CMs were electrically paced. A cardiac-specific, inducible knockout mouse (Tax1bp3-/-) was made and intracardiac electrophysiology studies conducted to observe arrhythmia inducibility following pacing.

We identified a kindred with multiple members affected by ACM cosegregating with biallelic variants in the gene TAX1BP3, which encodes the protein TAX1BP3 (Tax1-binding protein 3). iPSC-CMs derived from this kindred demonstrated increased intracellular lipid droplets, induction of TRPV4 (transient receptor potential vanilloid type 4) expression, and inducible TRPV4 current. This was associated with depletion of the intracellular sarcoplasmic reticulum Ca2+ store and increased RyR2 (ryanodine receptor 2)-mediated store Ca2+ leak and delayed afterdepolarizations, a known mechanism of Ca2+-mediated arrhythmogenesis. Similarly, Tax1bp3 cardiac-specific knockout mice had increased Ca2+ leak and were predisposed to ventricular arrhythmias compared with wild-type mice. Ca2+ leak in both the iPSC-CMs and mouse ventricular myocytes was rescued by small molecule TRPV4 inhibition. This strategy also effectively reduced Ca2+ leak in a PKP2 (plakophilin 2) p.His773AlafsX8 iPSC-CM model of ACM.

We conclude that TAX1BP3 is associated with rare autosomal recessive ACM through TRPV4-mediated Ca2+ leak from RyR2. Further, TRPV4 current inhibition has the potential to be a new therapeutic target for ACM.

To investigate the exome sequencing (ES) detection rate among fetuses with congenital anomalies and describe the rates in the setting of multiple versus isolated anomalies, perinatal autopsy, and family history of a previously affected child.

A single-center retrospective chart review was conducted on 397 anomalous fetuses that underwent ES from May 2012 through December 2023. Medical record review included demographics, imaging, and genetic testing.

The overall ES diagnostic rate was 34.3%. The rate of diagnosis was 31.6% in fetuses with a single anomaly and 42.6% in fetuses with 4 or more major organ systems involved. Of the fetuses with a single anomaly, lymphatic, craniofacial, skeletal, and neurological anomalies had the highest diagnostic rate on ES. 38.6% of deceased fetuses who underwent autopsy had a genetic diagnosis. Additionally, families who had a previously affected child had a 45.5% diagnostic rate.

ES is an important tool that should be offered in pregnancies affected with congenital abnormalities or at the time of fetal demise or termination. The diagnostic rate of ES in the prenatal setting is also highly dependent on comprehensive phenotyping. With diagnostic ES results, reproductive technology and testing options are available in subsequent pregnancies.

Affecting fewer than 20,000 people as defined in South Korea, rare diseases pose significant diagnostic challenges due to their diverse manifestations and genetic heterogeneity. Genome sequencing (GS) offers a promising solution by enabling simultaneous screening for thousands of rare genetic disorders. This study explores the diagnostic utility and necessity of GS within the government-funded Korean Regional Rare Disease Diagnostic Support Program (KR-RDSP), a collaborative initiative involving 11 regional rare disease centers across Korea. The program was launched as a proof-of-concept study in 2023 to equip the genetic clinics with a diagnostic tool to expedite the diagnoses for rare disease patients who reside outside the urban Seoul region where diagnostic resources are limited. The study leveraged GS to diagnose a cohort of 400 patients exhibiting a wide spectrum of symptoms. The overall diagnostic yield was 36.3% (145/400), with 4.8% (7/145) of the diagnosed patients being reported with variants that could not have been identified by chromosomal microarray or exome sequencing (ES), highlighting the added value of comprehensive genomic analysis. The implementation of a centralized GS analysis system streamlined the diagnostic process, enabling timely reporting within a reasonable turnaround time of ≤ 35 days. Segregation analysis by Sanger sequencing played a crucial role in confirming or reclassifying variant pathogenicity by elucidating inheritance patterns. Here, we summarize diagnostic statistics from the 400 GS dataset gathered from June 2023 to December 2023 and show interesting and informative case examples that illustrate the diagnostic efficacy of GS, highlighting its ability to uncover elusive genetic etiologies and provide personalized treatment insights. The study also highlights the successful implementation of the program for the 11 regional rare disease centers across Korea with a practical workflow, comprehensive testing, comparable diagnostic yield to previous reports, and, most importantly, reasonable turnaround time.

Exome sequencing is the current standard for diagnosing Mendelian disorders; however, it is generally not considered the first-line test for detecting copy number variants (CNVs). We retrospectively investigated the additional diagnostic yield by performing concurrent CNV analysis using exome data in a large and diverse pediatric cohort. Patients were referred from various sources with variable phenotypes. Human Phenotype Ontology terms were used to prioritize variants for analysis. Ancestry and CNV analyses were performed using Somalier and NxClinical, respectively. A total of 1538 patients were tested, with the majority being Admixed Americans. Diagnostic CNVs were identified in 70 patients (4.6%), ranging from exonic deletions to large, unbalanced rearrangements, aneuploidies, and mosaic findings. While no significant differences were identified in diagnostic yield, or rates of negative or uncertain diagnoses, between ancestries, our study demonstrates the feasibility and increased yield of CNV analysis of exome data, across multiple phenotypes, referral sources, and ancestries.

Mutations in the KAT6A gene, which encodes a histone acetyltransferase, have been linked to an autosomal dominant neurodevelopmental disorder known as the Arboleda-Tham syndrome. The clinical symptoms of this disorder are nonspecific and pose challenges to accurately characterizing the condition based solely on these symptoms. This study aimed to establish a definitive diagnosis in three patients with intellectual disability and multiple congenital anomalies, and to elucidate the genotype-phenotype correlation based on the existing literature.

In this study, we investigated three probands with severe intellectual disability, global developmental delay, hypotonia, gait disturbance, microcephaly, scoliosis, abnormal heart morphology, strabismus, gastrointestinal dysmotility, and abnormal facial shape, using karyotype analysis, multiplex ligation-dependent probe amplification, and whole exome sequencing. We also conducted a comprehensive literature review of previously reported cases.

The karyotype analysis and Multiplex ligation-dependent probe amplification results were normal. Whole exome sequencing revealed three novel de novo mutations, c.3712G > T (p.Glu1238*), c.3561 C > A (p.Cys1187*), and c.1069 C > T (p.Arg357*), in the KAT6A gene (NM_006766.5). The heterozygous variants were verified by Sanger sequencing and were not present in either parent.

In this study, we describe three cases of de novo KAT6A variants that were identified for the first time in Iran. Our results expand the understanding of the clinical features associated with Arboleda-Tham syndrome and validate the effectiveness of whole-exome sequencing to rapidly and accurately determine the etiology of such disorders. Furthermore, our literature review demonstrated close genotype-phenotype correlations associated with KAT6A and Arboleda-Tham syndrome.

BCL11B is a Cys2-His2 zinc-finger (C2H2-ZnF) domain-containing, DNA-binding, transcription factor with established roles in the development of various organs and tissues, primarily the immune and nervous systems. BCL11B germline variants have been associated with a variety of developmental syndromes. However, genotype-phenotype correlations along with pathophysiologic mechanisms of selected variants mostly remain elusive. To dissect these, we performed genotype-phenotype correlations of 92 affected individuals harboring a pathogenic or likely pathogenic BCL11B variant, followed by immune phenotyping, analysis of chromatin immunoprecipitation DNA-sequencing data, dual-luciferase reporter assays, and molecular modeling. These integrative analyses enabled us to define three clinical subtypes of BCL11B-related disorders. It is likely that gene-disruptive BCL11B variants and missense variants affecting zinc-binding cysteine and histidine residues cause mild to moderate neurodevelopmental delay with increased propensity for behavioral and dental anomalies, allergies and asthma, and reduced type 2 innate lymphoid cells. Missense variants within C2H2-ZnF DNA-contacting α helices cause highly variable clinical presentations ranging from multisystem anomalies with demise in the first years of life to late-onset, hyperkinetic movement disorder with poor fine motor skills. Those not in direct DNA contact cause a milder phenotype through reduced, target-specific transcriptional activity. However, missense variants affecting C2H2-ZnFs, DNA binding, and "specificity residues" impair BCL11B transcriptional activity in a target-specific, dominant-negative manner along with aberrant regulation of alternative DNA targets, resulting in more severe and unpredictable clinical outcomes. Taken together, we suggest that the phenotypic severity and variability is largely dependent on the DNA-binding affinity and specificity of altered BCL11B proteins.

Chromosomal microarray analysis (CMA) has been central to prenatal genetic diagnosis, detecting copy number variants with a ∼1% yield in low-risk cases. Next-generation sequencing (NGS), including exome sequencing (ES), enhances diagnostic capabilities with higher yields (8.5-10%) but at greater cost and complexity. While ES's cost-effectiveness is studied in high-risk pregnancies, data for low-risk pregnancies remain lacking. This study evaluates the cost-effectiveness of ES in low-risk pregnancies.

This study aimed to investigate the cost-effectiveness of exome sequencing compared with chromosomal microarray analysis.

Costs, utilities, and quality-adjusted life years were modeled for prenatal testing with chromosomal microarray analysis or chromosomal microarray analysis + exome sequencing. Average costs and utilities were discounted at 3%. In addition, 2 strategies for screening were compared using the Markovian decision analysis model: (1) chromosomal microarray analysis only (an abnormal result leads to a termination of pregnancy, and a normal test has a 1 to 160 chance of developing into a severe disorder) and (2) exome sequencing after a normal chromosomal microarray analysis (a positive result leads to a termination of pregnancy). Of note, 1-way sensitivity analysis was performed for all variables. The outcome measures included quality-adjusted life years after abortion, costs of chromosomal microarray analysis and exome sequencing, and health expenses of a critically ill infant. The time horizon of the model was 20 years.

The total costs were $1348 for chromosomal microarray analysis and $3108 for chromosomal microarray analysis + exome sequencing. The quality-adjusted life years with a time horizon of 20 years were 14.15 for chromosomal microarray analysis and 14.19 for chromosomal microarray analysis + exome sequencing, with an incremental cost-effectiveness ratio of $46,383 per quality-adjusted life years. Sensitivity analysis revealed that the time horizon and the disutility of moderate/severe disability of the genetic disorder have an effect on the incremental cost-effectiveness ratio. For example, the incremental cost-effectiveness ratios are $84,291 per quality-adjusted life years for a relatively small disutility of moderate/severe disability and $94,148 per quality-adjusted life years for a shorter time horizon of 10 years.

Exome sequencing has the potential to be cost-effective compared with chromosomal microarray analysis alone. Our research provides data regarding the cost-effectiveness of exome sequencing without a specific indication, which will become increasingly important in the near future as whole exome sequencing becomes the first-tier test in prenatal diagnosis.

Adult patients with undiagnosed genetic disorders suffer most from diagnostic delay and seldom appear in cohort studies investigating the diagnostic yield in medical genetic clinical practice. Here we present the results of the diagnostic activity performed in a referral center on 654 consecutive, unselected adult subjects presenting with molecularly unsolved conditions. More than 50% of the referred individuals were affected by syndromic or isolated intellectual disability. Different molecular approaches, including clinical/whole exome sequencing (CES/WES), chromosomal microarray analysis (CMA), and/or targeted gene or gene panel sequencing were used to analyze patients' DNA. Definitive diagnosis was obtained in over 30% of individuals. The most sensitive methodology was CES/WES, which allowed us to reach a diagnosis in over 50% of the 162 solved cases. Despite the great variety of clinical presentations, our results represent a reliable picture of the "real world" daily routine in an outpatient medical genetics clinic dedicated to diagnostic activity, and contribute to better understand the great value of a definitive molecular diagnosis in adults, either for the affected individuals and their families. This retrospective analysis demonstrates the importance of adopting a genomic-first approach within the diagnostic process for adults affected with unsolved rare conditions.

Report the prevalence of multiple genetic diseases in the Undiagnosed Diseases Network (UDN) cohort in the post-exome-sequencing era. UDN subjects underwent genome sequencing before inclusion in the cohort. Records of all UDN subjects until January 2024 were analyzed. The number of diagnoses, proportion of molecular versus nonmolecular (i.e., not attributable to a discretely identifiable genetic change) diagnoses, and the inheritance patterns of the genetic diagnoses were determined. Of 2799 subjects, 766 (27.4%) had diagnoses. Of these 766, 95.4% had one diagnosis, 4.0% had two diagnoses, and 0.5% had three diagnoses. Of the diagnosed subjects, 93.4% had a genetic disease, and 6.5% had a nonmolecular disease. Of subjects with two diagnoses, both diagnoses were molecular in 90.3%, while 9.7% had one molecular and one nonmolecular diagnosis. All four subjects with three diagnoses had three molecular diagnoses. 4.2% of diagnosed subjects in the UDN had more than one molecular diagnosis, with four individuals having three concurrent Mendelian diagnoses. Additionally, three subjects had concurrent molecular and nonmolecular diagnoses. Given that numerous UDN subjects had a negative genome sequence prior to UDN enrollment, multiple molecular diagnoses may contribute to diagnostic uncertainty even with genome sequencing, as may concurrent nonmolecular disease.

Ultra rare disorders are being diagnosed at an unprecedented rate, due to genomic sequencing. These diagnoses are often a new gene association, for which little is known, and few share the diagnosis. For these diagnoses, we use the term emerging-ultrarare disorder (E-URD), defined as <100 diagnosed individuals. We contacted 20 parents of children diagnosed with an E-URD through the Duke University Research Sequencing Clinic. Seventeen completed semi-structured interviews exploring parental perspectives (7/17 had children in publications describing the phenotype; 4/17 had children in the first publication establishing a new disorder). Data were analyzed using a directed content approach informed by an empowerment framework. Parents reported a range of responses, including benefits of a diagnosis and challenges of facing the unknown, some described feeling lost and confused, while others expressed empowerment. Empowerment characteristics were hope for the future, positive emotions, engagement, and confidence/self-efficacy to connect with similar others, partner with healthcare providers, and seek new knowledge. We identified a subset of parents who proactively engaged researchers, supported research and publications, and created patient advocacy and support organizations to connect with and bolster similarly diagnosed families. Other parents reported challenges of low social support, low tolerance for uncertainty, limited knowledge about their child's disorder, as well as difficulty partnering with HCPs and connecting to an E-URD community. An overarching classification was developed to describe parental actions taken after an E-URD diagnosis: adjusting, managing, and pioneering. These classifications may help genetic counselors identify and facilitate positive steps with parents of a child with an E-URD.

We investigated the effectiveness of exome sequencing (ES) in diagnosing ethnically diverse patients with rare genetic disorders. A total of 18,994 patients referred to a single reference laboratory for ES between 2020 and 2022 were studied for the diagnostic rate and factors influencing the diagnostic rate. The overall diagnostic rate was 31.8%. Dermatological disorders, skeletal disorders, and neurodevelopmental disorders disease categories, early age-of-onset, presence of consanguinity, and the presence of parental sequencing data were found to be correlated with a higher diagnostic rate. Nearly 68K variants were identified in our dataset at a higher frequency than that observed in gnomAD 4.0. Of these, 507 variants could be classified as likely benign, representing 0.04% of non-benign variants in ClinVar (507/1,433,904) and 0.20% of the non-benign ClinVar variants observed at least once in our cohort (507/276,777). The overall diagnostic rate is comparable to that observed in other large cohort studies with less diverse ethnic backgrounds.

F-BAR domain only protein 1 (FCHO1) contributes as a critical component to an essential cellular process, clathrin-mediated endocytosis. Clathrin-mediated endocytosis involves cellular membrane invagination followed by cargo protein recruitment and adaptor protein assembly to form endocytic vesicles and maintains several cellular functions, such as signaling, differentiation, nutrition, absorption, and secretion. We aimed to determine the clinical/immunological findings of FCHO1 deficiency to generate an appropriate medical approach. We present clinical/immunological/genetic findings of two FCHO1 deficiency patients together with recently reported 17 patients. We found two different variants in the patients, one previously defined and one novel homozygous mutation [c.306C > A (p.Tyr102Ter)]. Recurrent sinopulmonary infections occurred in all patients, with viral (63.1%) and fungal (52.6%) infections frequently reported. Lymphopenia and CD4 + T cell lymphopenia are present in 77.7% (14/18) and 100% of patients, respectively. CD8+ T cell number is low in half. Hypogammaglobulinemia and low IgM are present in 83.3% (15/18) and 61.1% (11/18) of patients, respectively. Neurological disorders (Guillian-Barre Syndrome, Moya-Moya disease, encephalitis, and cranial infarction) are common [n = 6 (31.5%)]. Malignancy is present in four (21%) patients, three suffered from diffuse large B cell lymphoma, and one developed Hodgkin lymphoma. Additional clinical and laboratory results from more patients helped to define the characteristics of FCHO1 deficiency. The early application of molecular genetic analysis in CID patients is crucial. Since all transplanted patients were alive, allogeneic hematopoietic stem cell transplantation emerged as a potential curative therapy.

Pathology, a cornerstone of medical diagnostics and research, is undergoing a revolutionary transformation fueled by digital technology, molecular biology advancements, and big data analytics. Digital pathology converts conventional glass slides into high-resolution digital images, enhancing collaboration and efficiency among pathologists worldwide. Integrating artificial intelligence (AI) and machine learning (ML) algorithms with digital pathology improves diagnostic accuracy, particularly in complex diseases like cancer. Molecular pathology, facilitated by next-generation sequencing (NGS), provides comprehensive genomic, transcriptomic, and proteomic insights into disease mechanisms, guiding personalized therapies. Immunohistochemistry (IHC) plays a pivotal role in biomarker discovery, refining disease classification and prognostication. Precision medicine integrates pathology's molecular findings with individual genetic, environmental, and lifestyle factors to customize treatment strategies, optimizing patient outcomes. Telepathology extends diagnostic services to underserved areas through remote digital pathology. Pathomics leverages big data analytics to extract meaningful insights from pathology images, advancing our understanding of disease pathology and therapeutic targets. Virtual autopsies employ non-invasive imaging technologies to revolutionize forensic pathology. These innovations promise earlier diagnoses, tailored treatments, and enhanced patient care. Collaboration across disciplines is essential to fully realize the transformative potential of these advancements in medical practice and research.

Hypomyelinating leukodystrophies are a group of genetic disorders, characterised by severe permanent myelin deficiency. Their clinical features include developmental delay with or without neuroregression, nystagmus, central hypotonia, progressing to spasticity and ataxia. HSPD1 encodes the HSP60 chaperonin protein, mediating ATP-dependent folding of imported proteins in the mitochondrial matrix. Pathogenic variants in HSPD1 have been related to a number of neurological phenotypes, including the dominantly inherited pure hereditary spastic paraplegia (MIM 605280) and the recessively inherited hypomyelinating leukodystrophy 4 (MIM 612233). Subsequently, an additional phenotype of hypomyelinating leukodystrophy has been reported due to de novo heterozygous HSPD1 variants.In the current work, we expand the clinical and genetic spectrum of this hypomyelinating disorder by describing a cohort of three patients, being heterozygous for HSPD1 variants involving residue Ala536 of HSP60 (the novel p.Ala536Pro variant and the previously reported p.Ala536Val).

Clinical and radiological evaluation; whole exome sequencing, in vitro reconstitution assay and patient fibroblast cell lysate analysis.

Clinical manifestation was of early-onset nystagmus, tremor and hypotonia evolving into spasticity and ataxia and childhood-onset neuroregression in one case. Brain MRI studies revealed diffuse hypomyelination.The 3D protein structure showed these variants to lie in spatial proximity to the previously reported Leu47Val variant, associated with a similar clinical phenotype. In vitro reconstitution assay and patient fibroblast cell lysate analysis demonstrated that these mutants display aberrant chaperonin protein complex assembly.

We provide evidence that impaired oligomerisation of the chaperonin complex might underlie this HSPD1-related phenotype, possibly through exerting a dominant negative effect.

Autosomal recessive congenital ichthyosis (ARCI) is a group of genetic skin disorders characterized by abnormal keratinization, leading to significant health issues and reduced quality of life. ARCI encompasses harlequin ichthyosis (HI), congenital ichthyosiform erythroderma (CIE), and lamellar ichthyosis (LI). While all ARCI genes are linked to LI and CIE, HI is specifically associated with severe mutations in the ABCA12 gene. Milder forms like LI and CIE usually involve at least one non-truncating ABCA12 variant.

Whole-exome sequencing (WES) was performed on fetal and parental DNA, and ABCA12 gene variants were validated by Sanger sequencing. The functional effect of the novel variant c.7104 + 6T > A was evaluated using an in vitro minigene system, with splicing analysis conducted via PCR and Sanger sequencing.

A compound heterozygous variation in the ABCA12 gene, comprising c.5784G > A (p.W1928*) and c.7104 + 6T > A, was identified in the fetus, inherited from the father and mother, respectively. According to ACMG guidelines, the c.7104 + 6T > A variant is classified as a Variant of Uncertain Significance (VUS). Computational predictions suggested that this variant affects splicing. A minigene assay further confirmed that the c.7104 + 6T > A variant in ABCA12 leads to two types of aberrant mRNA splicing: a 69-base pair deletion (c.7036_7104del, p.Val2346_Glu2368del) and skipping of Exon 47, both of which result in a premature stop codon and a truncated protein.

In conclusion, this study identified a novel genetic variant, c.7104 + 6T > A in ABCA12, as the cause of ARCI in a fetus, thereby enriched the known ABCA12 mutation spectrum.

Mode of inheritance (MOI) is necessary for clinical interpretation of pathogenic variants; however, the majority of variants lack this information. Furthermore, variant effect predictors are fundamentally insensitive to recessive-acting diseases. Here, we present MOI-Pred, a variant pathogenicity prediction tool that accounts for MOI, and ConMOI, a consensus method that integrates variant MOI predictions from three independent tools. MOI-Pred integrates evolutionary and functional annotations to produce variant-level predictions that are sensitive to both dominant-acting and recessive-acting pathogenic variants. Both MOI-Pred and ConMOI show state-of-the-art performance on standard benchmarks. Importantly, dominant and recessive predictions from both tools are enriched in individuals with pathogenic variants for dominant- and recessive-acting diseases, respectively, in a real-world electronic health record (EHR)-based validation approach of 29,981 individuals. ConMOI outperforms its component methods in benchmarking and validation, demonstrating the value of consensus among multiple prediction methods. Predictions for all possible missense variants are provided in the "Data and code availability" section.

Alström syndrome (ALMS), a rare recessively inherited ciliopathy caused by mutations in ALMS1, is characterized by retinal dystrophy, childhood obesity, sensorineural hearing loss, and type 2 diabetes mellitus. The majority of pathogenic variants in ALMS1 are nonsense and frameshift mutations, which would lead to premature protein truncation, whereas copy number variants are seldom reported.

Herein, we present a 10-year-old Chinese girl with ALMS. The potential causative genetic variant was confirmed through whole genome sequencing, quantitative real-time PCR analysis, and Sanger sequencing. Additionally, breakpoint analysis was performed to determine the exact breakpoint site of the large deletion and elucidate its probable formation mechanism.

The patient had a cor triatriatum sinister (CTS) structure. Genetic analysis identified novel compound heterozygous variants in the patient, consisting of a frameshift variant c.4414_4415delGT (p.V1472Nfs*26) in ALMS1 and a novel large deletion at chr2:73,612,355-73,626,339, which encompasses exon 1 of the ALMS1 gene. Moreover, breakpoint analysis revealed that the large deletion probably formed through the microhomology-mediated end joining (MMEJ) mechanism due to the 6-bp microhomologies (TCCTTC) observed at both ends of the breakpoints.

In this study, novel compound heterozygous variants in the ALMS1 gene were identified in an ALMS patient with a CTS structure. The molecular confirmation of these variants expands the mutational spectrum of ALMS1, while the manifestation of ALMS in the patient provides additional clinical insights into this syndrome.

Focal segmental glomerulosclerosis (FSGS) is a leading kidney disease, clinically associated with proteinuria and progressive renal failure. The occurrence of this disease is partly related to gene mutations. We describe a single affected family member who presented with FSGS. We used high-throughput sequencing, sanger sequencing to identify the pathogenic mutations, and a systems genetics analysis in the BXD mice was conducted to explore the genetic regulatory mechanisms of pathogenic genes in the development of FSGS. We identified high urinary protein (++++) and creatinine levels (149 μmol/L) in a 29-year-old male diagnosed with a 5-year history of grade 2 hypertension. Histopathology of the kidney biopsy showed stromal hyperplasia at the glomerular segmental sclerosis and endothelial cell vacuolation degeneration. Whole-exome sequencing followed by Sanger sequencing revealed a heterozygous missense mutation (c.643C > T) in exon 2 of TRPC6, leading to the substitution of arginine with tryptophan at position 215 (p.Arg215Trp). Systems genetics analysis of the 53 BXD mice kidney transcriptomes identified Pygm as the upstream regulator of Trpc6. Those two genes are jointly involved in the regulation of FSGS mainly via Wnt and Hippo signaling pathways. We present a novel variant in the TRPC6 gene that causes FSGS. Moreover, our data suggested TRPC6 works with PYGM, as well as Wnt and Hippo signaling pathways to regulate renal function, which could guide future clinical prevention and targeted treatment for FSGS outcomes.

Genome-wide sequencing, which includes exome sequencing and genome sequencing, has revolutionized the diagnostics of genetic disorders in both postnatal and prenatal settings. Compared to exome sequencing, genome sequencing enables the detection of many additional types of genomic variants, although this depends on the bioinformatics pipelines used. Variant classification might vary among laboratories. In the prenatal setting, variant classification may change if new fetal phenotypic features emerge as the pregnancy progresses. There is still a need to evaluate the incremental diagnostic yield of genome sequencing compared to exome sequencing in the prenatal setting. This article reviews the advantages and limitations of genome sequencing, with an emphasis on fetal diagnostics.

Mitochondrial DNA depletion syndromes (MDDSs) are a group of clinically and genetically heterogeneous disorders. In the present study, we aimed to investigate the frequency of MDDS in children under the age of 5 years with suspected mitochondrial hepatopathy and to evaluate this group of patients using MDDS gene panel and clinical exome sequencing (CES) genetic analysis methods.

Patients under 5 years of age who were clinically suspected to have mitochondrial hepatopathy and had neonatal acute liver failure, hepatic steatohepatitis, cholestasis, or cirrhosis with chronic liver failure of insidious onset were included.

Forty patients (20 female, 50%) were enrolled, with a median age of 102 [57-263.8] days. Icteric appearance was identified in 28 (70%) of the patients, hepatomegaly in 27 (67.5%), splenomegaly in 10 (25.0%), and hypotonicity in 10 (25.0%); moreover, elevated international normalized ratio was detected in 77.5%, cholestasis in 77.5%, and elevated lactate levels in 62.5%. Molecular genetic diagnosis was made in 9 patients (22.5%) with the MDDS gene panel and in 17 (42.5%) patients with the CES analysis. All patients diagnosed with MDDS had a history of parental consanguinity, while the rate in those without MDDS was 54.8% (p = 0.012). High lactate levels were identified in all those with MDDS, but in only 51.6% of those without MDDS (p = 0.020).

Present study revealed that demographic findings and laboratory assessments are insufficient to diagnose genetically inherited diseases in children presenting with hepatic involvement. While one-fifth of the patients with suspected mitochondrial hepatopathies were diagnosed with MDDS, it is revealed that around half of patients can be diagnosed with CES panel.

Genetic testing for prenatal diagnosis in the pre-genomic era primarily focused on detecting common fetal aneuploidies, using methods that combine maternal factors and imaging findings. The genomic era, ushered in by the emergence of new technologies like chromosomal microarray analysis and next-generation sequencing, has transformed prenatal diagnosis. These new tools enable screening and testing for a broad spectrum of genetic conditions, from chromosomal to monogenic disorders, and significantly enhance diagnostic precision and efficacy. This chapter reviews the transition from traditional karyotyping to comprehensive sequencing-based genomic analyses. We discuss both the clinical utility and the challenges of integrating prenatal exome and genome sequencing into prenatal care and underscore the need for ethical frameworks, improved prenatal phenotypic characterization, and global collaboration to further advance the field.

Autosomal recessive cerebellar ataxias (ARCA) are rare heterogenous neurodegenerative disorders characterized by degeneration of the cerebellum and spinal cord with an early onset before the age of 20 years. PMPCA (MIM: 613036), is a key enzyme in mitochondrial protein processing which is critical for cell survival and growth. Our objective was to investigate Peptidase, Mitochondrial Processing Subunit Alpha (PMPCA) mutations linked with Spinocerebellar ataxia, autosomal recessive 2 (SCAR2).

In the current study, Whole Exome Sequencing (WES) was done followed by Sanger sequencing for the validation of the WES results.

WES results identified a novel homozygous variant, NM_015160.2: c.802C>T p.(Arg268Trp) in PMPCA gene. Mutation in this gene leads to progressive cerebellar ataxia with fine motor skills difficulties, intentional tremors, slow slurred speech and learning difficulties in a 12-year-old Saudi patient. WES results were further validated by Sanger sequencing technique.

Identified phenotype in our case was similar as previously described for SCAR2 related conditions. To our knowledge, this is the first reported mutation in PMPCA gene leading to SCAR2 in Saudi Arabia. These findings will enrich the scarce literature, further provide a new insight on the role of PMPCA gene-related disorders leading to SCAR2 and expand the disease concept. In addition, this will help to establish a database for the disease and its causative factors will further help in controlling diseases resulting from consanguinity in Saudi population.

Inherited bone marrow failure syndromes (IBMFS) pose significant diagnostic challenges due to overlapping symptoms and variable expressivity, despite evolving genomic insights. The study aimed to elucidate the genomic landscape among 130 Korean patients with IBMFS. We conducted targeted next-generation sequencing (NGS) and clinical exome sequencing (CES) across the cohort, complemented by whole genome sequencing (WGS) and chromosomal microarray (CMA) in 12 and 47 cases, respectively, with negative initial results. Notably, 50% (n = 65) of our cohort achieved a genomic diagnosis. Among these, 35 patients exhibited mutations associated with classic IBMFSs (n = 33) and the recently defined IBMFS, aplastic anaemia, mental retardation and dwarfism syndrome (AmeDS, n = 2). Classic IBMFSs were predominantly detected via targeted NGS (85%, n = 28) and CES (88%, n = 29), whereas AMeDS was exclusively identified through CES. Both CMA and WGS aided in identifying copy number variations (n = 2) and mutations in previously unexplored regions (n = 2). Additionally, 30 patients were diagnosed with other congenital diseases, encompassing 13 distinct entities including inherited thrombocytopenia (n = 12), myeloid neoplasms with germline predisposition (n = 8), congenital immune disorders (n = 7) and miscellaneous genomic conditions (n = 3). CES was particularly effective in revealing these diverse diagnoses. Our findings underscore the significance of comprehensive genomic analysis in IBMFS, highlighting the need for ongoing exploration in this complex field.

Currently, whole exome sequencing has been performed as a helpful complement in the prenatal setting in case of fetal anomalies. However, data on its clinical utility remain limited in practice. Herein, we reported our data of fetal exome sequencing in a cohort of 512 trios to evaluate its diagnostic yield.

In this retrospective cohort study, the couples performing prenatal exome sequencing were enrolled. Fetal phenotype was classified according to ultrasound and magnetic resonance imaging findings. Genetic variants were analyzed based on a phenotype-driven followed by genotype-driven approach in all trios.

A total of 97 diagnostic variants in 65 genes were identified in 69 fetuses, with an average detection rate of 13.48%. Skeletal and renal system were the most frequently affected organs referred for whole exome sequencing, with the highest diagnostic rates. Among them, short femur and kidney cyst were the most common phenotype. Fetal growth restriction was the most frequently observed phenotype with a low detection rate (4.3%). Exome sequencing had limited value in isolated increased nuchal translucency and chest anomalies.

This study provides our data on the detection rate of whole exome sequencing in fetal anomalies in a large cohort. It contributes to the expanding of phenotypic and genotypic spectrum.

Cornelia de Lange syndrome (CdLS) is an uncommon congenital developmental disorder distinguished by intellectual disorder and distinctive facial characteristics, with a minority of cases attributed to RAD21 variants.

A patient was admitted to the endocrinology department at Peking Union Medical College Hospital, where 2 mL of peripheral venous blood was collected from the patient and his parents. DNA was extracted for whole-exome sequencing (WES) analysis, and the genetic variation of the parents was confirmed through Sanger sequencing.

A 13.3-year-old male patient with a height of 136.5 cm (-3.5 SDS) and a weight of 28.4 kg (-3.1 SDS) was found to have typical craniofacial features. WES revealed a pathogenic variant c.1143G>A (p.Trp381*) in the RAD21 gene. He was diagnosed with CdLS type 4 (OMIM #614701). We reviewed 36 patients with CdLS related to RAD21 gene variants reported worldwide from May 2012 to March 2024. Patient's variant status, clinical characteristics, and rhGH treatment response were summarized. Frameshift variants constituted the predominant variant type, representing 36% (13/36) of cases. Clinical features included verbal developmental delay and intellectual disorder observed in 94% of patients.

This study reported the third case of CdLS type 4 in China caused by a RAD21 gene variant, enriching the genetic mutational spectrum.

Childhood epilepsies are caused by heterogeneous underlying disorders where approximately 40% of the origins of epilepsy can be attributed to genetic factors. The application of next-generation sequencing (NGS) has revolutionized molecular diagnostics and has enabled the identification of disease-causing genes and variants in childhood epilepsies. The objective of this study was to use NGS to identify variants in patients with childhood epilepsy, to expand the variant spectrum and discover potential therapeutic targets.

In our study, 55 children with epilepsy of unknown etiology were analyzed by combining clinical-exome and whole-exome sequencing. Novel variants were characterized using various in silico algorithms for pathogenicity and structure prediction.

The molecular genetic cause of epilepsy was identified in 28 patients and the overall diagnostic success rate was 50.9%. We identified variants in 22 different genes associated with epilepsy that correlate well with the described phenotype. SCN1A gene variants were found in five unrelated patients, while ALDH7A1 and KCNQ2 gene variants were found twice. In the other 19 genes, variants were found only in a single patient. This includes genes such as ASH1L, CSNK2B, RHOBTB2, and SLC13A5, which have only recently been associated with epilepsy. Almost half of diagnosed patients (46.4%) carried novel variants. Interestingly, we identified variants in ALDH7A1, KCNQ2, PNPO, SCN1A, and SCN2A resulting in gene-directed therapy decisions for 11 children from our study, including four children who all carried novel SCN1A genetic variants.

Described novel variants will contribute to a better understanding of the European genetic landscape, while insights into the genotype-phenotype correlation will contribute to a better understanding of childhood epilepsies worldwide. Given the expansion of molecular-based approaches, each newly identified genetic variant could become a potential therapeutic target.