FREQUENCY OF R1193Q MUTATION IN SCNSA GENE ON SUSCEPTIBILITY FOR ARVC AND LQTS IN IRAN

Cardiomyopathy, a disease of the heart muscle, is associated with cardiac dysfunction and results to severe heart failure, arrhythmias, and death. Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a familial cardiomyopathy that is characterized by localized movement disorder in the wall of the right ventricle. Long QT syndrome (LQTS) is typical cardiac arrhythmia that causes hereditary or acquired cardiac arrest in patients with long QT interval and can be identified by electrocardiogram. It has been elucidated that R1193Q Polymorphism (R1193Q GGG> CAG, rs41261344)) is a functional substitution in sodium voltage-gated channel alpha subunit 5 (SCN5A) gene, and correlates with cardiac arrhythmia syndromes such as ARVC and LQTS. This case-control study was conducted to consider the correlation between SCN5A rs41261344 and cardiac arrhythmia syndromes in Iranian population. In the present study, 40 patients with LQTS, and 40 patients with ARVC, and 80 healthy subjects as controls were analyzed for SCN5A rs41261344 by polymerase chain reaction- restriction fragment length polymorphism (RFLP-PCR) and 10 samples from each group were sequenced. The SCN5A rs41261344 C allele with a frequency of 100% was present in all the patients and the healthy subjects. However, we did not observe SCN5A rs41261344 T allele in our enrolled subjects. In fact, the frequency of T allele was calculated zero. Regard to very low frequency of the R1193Q polymorphism minor allele, SCN5A rs41261344 T allele, in our cohort, it can be suggested that other mutations may be associated with cardiac arrhythmia syndromes such as ARVC and LQTS in Iranian population. Key Words: Cardiomyopathy, RFLP PCR, R1193Q polymorphism, SCN5A, ARVC, Long QT.