Evaluation of NaV1.5-related genes in Iranian Brugada Syndrome patients

Background:Brugada syndrome (BrS) is a primary arrhythmia syndrome characterized by right precordial ST elevation and intermittent right bundle-branch block, which may cause syncope and sudden cardiac death with a normal heart. At least seventeen genes are known to be causative for BrS. SCN5A gene mutations account 15-30% of index patients. Genetic screening of other genes slightly increases the diagnostics efficiency (7-8%).Frequency of mutations in different genes can be alsovarying significantly in populations. There was no systematic screening of Iranian BrS so far.Methods: A cohort of 50 unrelated Iranian BrS patients was investigated. Standard ECG, Echocardiography and flecainide challengetest was done. Screening of all coding exons and splice sites of α and β subunits related of NaV1.5 genes (SCN5A, SCN1b, SCN2b, SCN3b and SCN4b) and genes encoding NaV1.5 interacting proteins (SNTA1, CAV3 and MOG1) were performed by PCR-based and next generation sequencing and Sanger sequencing .Results: Nine mutations in SCN5A gene were found in index patients (р.A735V, р.Q778X, р.Y1434X, p.R1193W, р.R1316X, р.del_KPQ1505-1507, р.P1506S р.S1710L and р.R1929C), No rare non-synonymous variant was found in others genes inthis study. Conclusions: According to this study, the prevalence of SCN5A-positive probands in Iranian BrS group is 18%. We did not find any mutations in β subunits related of NaV1.5 genes and genes encoding NaV1.5-interacting proteins of BrS. The genetic screening of SCN5A gene can be proposed as a diagnostic tool for Iranian BrS patients. Genetic screening of calcium and potassium channel genes is planned for the same cohort

Keywords:

SCN5A , Brugada syndrome , NaV1.5