[Clinic and genetic polymorphism of Brugada syndrome in Russian patients, caused by mutation in SCN5A gene]

Abstract

Brugada syndrome (BrS) is an inherited cardiac arrhythmic disorder, characterized by ST-segment elevation in right precordial leads V1-V2>2 mm, pseudo right bundle branch block (RBBB), T-wave inversion and an increased risk of cardiac sudden death (SCD) due to molymorphic VT. It is estimated to be responsible for 12% of SCD cases and about 20% of deaths in patients with structurally normal hearts in autopsy. Mutations in the SCN5A gene account 15-30% of all cases. Clinical, instrumental and genetic analyses were performed for 25 Russian probands with BrS (19 males and 6 female). Phenotype-genotype correlation was studied in SCN5A-positive and SCN5A-negative patients. Rare genetic variants in SCN5A gene were found in 7 of 21 Russian probands (28%). Two variants affect protein splicing (c.IVS16DS-5A>G and c.IVS24AS+1G>A), three missense mutations (p,Y87C, p.R893H and p.S1787N), one in-frame deletion p.del848l, and one non-sense-mutation p.E553X. All mutations were unique for each family. There were no clinical or instrumental parameters were found to be effective in prediction of SCN5A mutations. The protocols of genetic counceling for SCN5A-positive and SCN5A-negative families were established.