Copyright: ©Author(s) 2026. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution-NonCommercial (CC BY-NC 4.0) license. No commercial re-use. See permissions. Published by Baishideng Publishing Group Inc.
World J Clin Pediatr. Jun 9, 2026; 15(2): 117629
Published online Jun 9, 2026. doi: 10.5409/wjcp.v15.i2.117629
Published online Jun 9, 2026. doi: 10.5409/wjcp.v15.i2.117629
Novel TMEM63A mutation associated with transient hypomyelination of infancy - lessons from a previously negative whole-exome sequencing case: Three case reports
Mongkol Chanvanichtrakool, Pimchanok Kulsirichawaroj, Watanawan Jaito, Surachai Likasitwattanakul, Division of Neurology, Department of Pediatrics, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand
Mongkol Chanvanichtrakool, Pimchanok Kulsirichawaroj, Surachai Likasitwattanakul, Pediatric Precision Medicine Center, Department of Pediatrics, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand
Pimchanok Kulsirichawaroj, Center of Research Excellence for Neuromuscular Diseases, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand
Theerapong Pho-Iam, Siriraj Genomics, Office of the Dean, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok 10700, Thailand
Wuttichart Kamolvisit, Department of Pediatrics, Center of Excellence for Medical Genomics, Faculty of Medicine, Chulalongkorn University, Bangkok 10700, Thailand
Author contributions: Chanvanichtrakool M and Likasitwattanakul S conceived and designed the study; Chanvanichtrakool M, Kulsirichawaroj P, Jaito W, and Pho-Iam T contributed to clinical data acquisition and patient evaluation; Pho-Iam T and Kamolvisit W performed genetic analyses and variant interpretation; Chanvanichtrakool M, Kulsirichawaroj P, Jaito W, and Likasitwattanakul S contributed to data analysis and manuscript preparation; Likasitwattanakul S supervised the project and provided critical revision of the manuscript; and all authors reviewed and approved the final version.
Informed consent statement: Written informed consent was obtained from the patients for publication of this report and accompanying images.
Conflict-of-interest statement: All authors declare that they have no conflict of interest to disclose.
CARE Checklist (2016) statement: The authors have read the CARE Checklist (2016), and the manuscript was prepared and revised according to the CARE Checklist (2016).
Corresponding author: Surachai Likasitwattanakul, MD, Associate Professor, Division of Neurology, Department of Pediatrics, Faculty of Medicine Siriraj Hospital, Mahidol University, 2 Wanglang Road, Bangkok Noi, Bangkok 10700, Thailand. surachai.lik@mahidol.ac.th
Received: December 12, 2025
Revised: January 25, 2026
Accepted: February 24, 2026
Published online: June 9, 2026
Processing time: 152 Days and 17.8 Hours
Revised: January 25, 2026
Accepted: February 24, 2026
Published online: June 9, 2026
Processing time: 152 Days and 17.8 Hours
Core Tip
Core Tip: Practice-changing diagnostic lesson: In children with early-onset nystagmus, hypotonia, and developmental delay-including hypomyelination syndrome-should be considered. When whole-exome sequencing is nondiagnostic, the appearance of new affected relatives or evolving new phenotype should trigger reanalysis using broader, iteratively refined human phenotype ontology terms, integrated with the suspected inheritance pattern. This strategy improves variant interpretation, increases diagnostic yield, and can ultimately end the diagnostic odyssey.