Compound heterozygous mutations of SH3TC2 in Charcot-Marie-Tooth disease type 4C patients.

Charcot-Marie-Tooth disease type 4C (CMT4C) is an autosomal recessive neuropathy caused by SH3TC2 mutations, characterized by spine deformities and cranial nerve involvement. This study identified four CMT4C families with compound heterozygous SH3TC2 mutations from 504 Korean demyelinating or intermediate CMT patients. The frequency of the CMT4C was calculated as 0.79% in demyelinating and intermediate patients (n = 504), but it was calculated as 2.02% in patients without PMP22 duplication (n = 198). The CMT4C frequency was similar to patients in Japan, but it was relatively low compared to those patients in other populations. The symptom was less severe and slowly progressed compared to the other AR-CMT. A patient harboring an intermediate neuropathy showed cranial nerve involvement but did not have scoliosis. This study will be helpful in making molecular diagnoses of demyelinating or intermediate CMT due to SH3TC2 mutations.