Clinical and genetic spectra of Charcot‐Marie‐Tooth disease in Chinese Han patients

Charcot‐Marie‐Tooth disease ( CMT ) is a common hereditary motor and sensory neuropathy. Epidemiological data for Chinese CMT patients are few. This study aimed to analyze the electrophysiological and genetic characteristics of Chinese Han patients. A total of 106 unrelated patients with the clinical diagnosis of CMT were included. Clinical examination, nerve conduction studies ( NCS ), next‐generation sequencing ( NGS ), and bioinformatic analyses were performed. Genetic testing was performed for 82 patients; 27 (33%) patients carried known CMT ‐associated gene mutations. PMP22 duplication was detected in 10 (12%) patients and GJB1 mutations in 9 (11%) patients. The mutation rate was higher in patients with a positive family history than in the sporadic cases (50% vs. 27%, p < 0.05). Six novel CMT ‐associated gene mutations including BSCL2 (c. 461C >T), LITAF (c. 32C >G), MFN2 (c. 497C >T), GARS (c. 794C >T), NEFL (c. 280C >T), and MPZ (c. 440T >C) were discovered. All except the LITAF (c. 32C >G) mutation were identified as “disease causing” via bioinformatic analyses. In this Chinese Han population, the frequency of PMP22 gene duplication in those with CMT1 was slightly (50% vs. 70%–80%) less than in Western/Caucasian populations. The novel CMT ‐associated gene mutations broaden the mutation diversity of CMT1 . NGS should be considered for genetic analyses in CMT patients.