Over the past 25 years, numerous SCN5A mutations have been associated with arrhythmic disorders, including congenital long QT syndrome type 3 (LQT3), Brugada syndrome (BrS), atrial fibrillation (AFib), progressive cardiac conduction defect (PCCD), sinus node dysfunction (SND), sudden infant death syndrome (SIDS), and dilated cardiomyopathy. The gene discussed is SCN5A; the disease is long QT syndrome 3.