Pediatric Cohort of Charcot-Marie-Tooth Disease: Clinical Features and Genetic Distribution.

Background and Objectives: Charcot-Marie-Tooth (CMT) disease is a heterogeneous group of hereditary peripheral neuropathies. While pediatric-onset CMT exhibits unique clinical and genetic characteristics, data on this subset remain sparse. This study investigates the clinical and genetic features of a pediatric CMT cohort in a single center in ON, Canada. Methods: A retrospective cross-sectional study reviewed data from patients diagnosed with CMT disease at The Hospital for Sick Children between 2013 and 2022. Genetic testing targeted up to 87 genes linked to CMT, with patient demographics, clinical features, electrodiagnostic findings, and orthopaedic complications analyzed using descriptive and inferential statistics. Results: Sixty-one patients from 14 genetically confirmed subtypes were included (29 female patients, 32 male patients). The median age at diagnosis was 7.7 years (range 1-17). Overall, foot deformities were present in 84% of patients, Achilles contractures in 42%, hammertoes in 28%, hip dislocation in 10%, and scoliosis in 23%. Discussion: This study provides a description of pediatric CMT disease in a Canadian cohort. We show that while genetic distributions mirror international data, family-based genetic screening can identify children even before clinical onset, and that orthopaedic complications are already common in early childhood. These findings reinforce the importance of early genetic confirmation, orthopaedic surveillance, and expanded sequencing strategies to improve care and refine genotype-phenotype correlations in pediatric CMT disease.