[Comparative study of gene mutation between Chinese patients with familial and sporadic hypertrophic cardiomyopathy].

ABSTRACT

OBJECTIVE: To compare the gene mutation between Chinese patients with familial and sporadic hypertrophic cardiomyopathy (HCM). METHODS: Peripheral blood samples were collected from 36 patients with familial HCM (FHCM) and 50 patients with sporadic HCM (SHCM), all un-related and from different provinces of China. PCR was used to amplify the 26 protein-coding axons of beta-myosin heavy chain (MYH7), 16 exons for cardiac troponin T (TNNT2), and 38 exons for cardiac myosin-binding protein C (MYBPC3). The amplified products were sequenced and compared with the standard sequence in the genBank so as to determine the potential mutation sites. RESULTS: (1) 13 of the 36 FHCM patients (36.1%) harbored 3 different mutations in MYH7 gene Arg663His in exon18, Glu924Lys in exon 23, and Ile736Thr in exon 20. Of the 50 SHCM patients, only 1 (2%) harbored MYH7 gene missence mutation Ile736Thr located in exon 20. (2) TNNT2 was not identified in all SHCM patients and FHCM patients. (3) MYBPC3 was not identified in all SHCM patients. Four FHCM patients harbored 2 different mutations Arg502Trp in exon 18 and Arg346fs in exon 13 respectively. CONCLUSION: MYH7 and MYBPC3 may be the dominant disease-causing genes in Chinese familial HCM patients; however the mutation rate of MYH7 and MYBPC3 genes is significantly lower in the SHCM patients compared with the FHCM patients. TNNT2 seems not the predominant disease-causing gene in all Chinese patients with HCM.