Moreover, mutations in SCN5A and auxiliary subunits genes (SCN1B-4B) have been found to be associated with a various inherited arrhythmia syndromes that includes BrS, long QT syndrome type 3 (LQT3), progressive cardiac conduction defect (PCCD), sick sinus node syndrome, atrial fibrillation and even dilated cardiomyopathy (DCM) [10]. The gene discussed is SCN5A; the disease is long QT syndrome 3.