Genetic variation screening of TNNT2 and MYH7 genes in a cohort of patients with hypertrophic and dilated cardiomyopathy
Abstract
Objectives: The mutations in genes for beta-myosin heavy chain (MYH7), and for troponin T (TNNT2) represent the majority of currently identifiable diseasecausing mutations of hypertrophic (HCM) and dilated (DCM) cardiomyopathy. The aim of the study was to analyze both MYH7 and TNNT2 exons in the patients with HCM and DCM diagnosis to improve the diagnostic and genetic consultancy in affected families.
Methods: All of the 15 exons and their flanking regions of TNNT2 gene were analysed by DNA sequence analysis and mutations R403L, R403Q, R403W, R663S, R663C in MYH7 gene were screened by RFLP analysis in 174 patients with HCM and DCM diagnosis. Results: We identified genetic variations in TNNT2 exon areas in 56 patients and genetic variations in TNNT2 intron areas in 164 patients.
Two patients were found to carry unique mutations in TNNT2 gene. Conclusions: The prevalence of malign TNNT2 gene mutations in our study cohort of patients with HCM born in Central Europe was less than 2%.
Nevertheless, specific genetic diagnostics of HCM is of marked value as it allows accurate family screening with identification of affected subject event without phenotypic expression of the disease. The study was supported by research projects MZO 0000VFN2005 (0000064165).