Objective: To identify potential mutation in a Chinese family affected with Charcot-Marie-Tooth disease(CMT).
Methods: Clinical data of the family was collected, and genomic DNA was extracted from peripheral blood samples of the family members. Seventy-two candidate genes of the proband were captured and sequenced by targeted next-generation sequencing, and the results were confirmed by Sanger sequencing. The protein structure was predicted with PyMOL-1 software.
Results: A homozygous missense mutation c.1894G>A(p.E632K) was identified in the exon 11 of the SH3TC2 gene in the proband. Heterozygous c.1894G>A mutation was also detected in the proband's father, mother and daughter, but not in the healthy family members and 300 normal controls. Retrieval of the NCBI, HGMD and 1000 genome databases has verified the c.1894G>A to be as a novel mutation. Computer simulation has suggested that the mutation has altered the 3D structure of the SH3TC2 protein.
Conclusion: The proband was diagnosed as CMT4C, for which the underlying gene was SH3TC2. This finding has expanded the spectrum of SH3TC2 mutation in association with CMT4C.