A homozygous SH3TC2 mutation in a Korean patient with Charcot–Marie–Tooth disease type 4C

Charcot–Marie–Tooth disease type 4C (CMT4C) is an autosomal recessive neuropathy associated with SH3TC2 mutations, resulting in slow conduction velocity via hypomyelination. The occurrence of CMT4C in demyelinating Charcot–Marie–Tooth (CMT) varies among ethnicities, and several variants have been reported as the founder mutation. In Korea, the incidence of CMT4C was calculated as approximately 2%, and all patients have compound heterozygous mutations, which is partly due to the prohibition of consanguineous marriage. Herein, we describe a 25-year-old male who presented a slowly progressive limb weakness and impaired vibration sensation. Whole-exome sequencing revealed homozygous variants c.929G>A of SH3TC2 after identifying negative multiplex ligation-dependent probe amplification results of PMP22. Based on our literature review, this is the first CMT4C patient with a homozygous variant with each allele inherited from both the parents.