Mutations in SCN5A have been primarily associated with pure arrhythmic disorders such as long QT syndromes (LQTs), Brugada syndrome (BrS), atrial fibrillation (AFib), progressive cardiac conduction defect (PCCD), and sinus node dysfuction (SND), all of which are inherited cardiac diseases. The gene discussed is SCN5A; the disease is familial long QT syndrome.