A high number of 'natural' mitochondrial DNA polymorphisms in a symptomatic Brugada syndrome type 1 patient

Brugada syndrome (BrS) is a rare genetic arrhythmic disorder with a complex model of transmission. At least 20 different genes have been identified as BrS-causal or susceptibility genes. Of these,SCN5Ais the most frequently mutated. Coregulation of different mutations or genetic variants, including mitochondrial DNA (mtDNA), may contribute to the clinical phenotype of the disease. In the present study, we analysed the mitochondrial genome of a symptomatic BrS type 1 patient to investigate a possible mitochondrial involvement recently found in the arrhytmogenic diseases. No pathogenic mutation was identified; however, a high number of single-nucleotide polymorphisms were found (n=21) and some of them were already been reported in molecular autopsy case for sudden death. The results reported here further support our hypothesis on the potential role of mtDNA polymorphisms in mitochondrial dysfunction, which may represent a risk factor for arrhythmogenic disease.