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.