The study on the modifying role of mitochondrial DNA polymorphism in the Brugada syndrome manifestation

Background : Brugada syndrome is a hereditary disease with genetic and phenotypic variability characterized by a high risk for arrhythmia and sudden cardiac death. It is assumed that  modifying genetic factors contribute to the variability of the phenotype. Mitochondrial DNA (mtDNA) polymorphism can be considered among such factors, since mitochondrial dysfunction, including that associated with mtDNA variants, can have an arrhythmogenic effect. Aim : To study possible association between mtDNA polymorphism with the phenotype in the Russian patients with Brugada syndrome. Materials and methods : We have studied mtDNA polymorphism in 36 Russian probands with Brugada syndrome. Common “European” haplogroups of mtDNA were assigned using sequencing of the hypervariable segment 1 in mtDNA D-loop. Results: In the study sample, the frequencies of the mtDNA haplogroups generally correspond to the distribution common for the Russian populations, except the J haplogroup, which was not found in the studied probands. The results contradict with previously published data on the J and T haplogroups as risk factors for Brugada syndrome manifestation. Conclusion : The study did not reveal the role of mtDNA polymorphism (J and T haplogroups) in the formation of the Brugada syndrome phenotype.