Genetic diversity of SCN5A gene and its possible association with the concealed form of Brugada syndrome development in Polish group of patients.

Brugada Syndrome (BS) is an inherited channelopathy associated with a high incidence of sudden cardiac death. The paper presents the discovery of new genetic variants of SCN5A gene which might be associated with the development of a concealed form of Brugada Syndrome. The study involved a group of 59 patients (37 men) with suspected concealed form of Brugada Syndrome. Pharmacological provocation with intravenous ajmaline administration was performed. Six patients with positive test results were subjected to molecular analysis of SCN5A gene with MSSCP method. Additionally, MSSCP genotyping was performed for samples obtained from the family members with Brugada Syndrome, despite the fact that they had negative ajmaline challenge test results. Genetic examinations of the SCN5A gene at 6 positive patients showed 6 known polymorphisms, 8 new single nucleotide point (SNP) variants located at exons, and 12 new single nucleotide point variants located at introns. Among new SNPs localized in SCN5A gene exons three SNPs affected the protein sequence.