Mutational analysis of the mitochondrial DNA detected in sudden cardiac death caused by cardiomyopathy

Objective: Comprehensive screening of mitochondrial DNA (mtDNA) was performed in consented autopsy cases diagnosed as cardiomyopathies (CMs), in order to evaluate the prevalence of gene mutations in sudden death caused by CM. Materials and Methods: Blood samples and left ventricular samples were obtained from 37 sudden cardiac death cases caused by CMs and 151 controls. DNA samples were amplified with the mitoSEQr Resequencing System and directly sequencing analyzed by the ABI 3130 genetic analyzer. Results: Missense mutations were detected in 42% of dilated cardiomyopathy (DCM) cases and in 20% of hypertrophic cardiomyopathy (HCM) cases. In coding regions, missense mutations detected only in CMs were 15 alterations in 8 cases with DCM and 3 alterations in 3 cases with HCM. Six new missense mutations were detected in this study. Haplogroups G1 and N9b were significantly more frequent in HCM and DCM compared to controls, respectively. Conclusions: It was considered that six new missense mutations in turn affected the ability of the essential components of the oxidative phosphorylation complexes. Genetic analysis of mtDNA was useful to decide diagnosis of CM for forensic autopsy cases. It was considered that and understanding the pathogenesis of CM could provide for genetic based diagnosis, risk stratification, treatment and prevention of cardiac phenotypes.