SCN5A and familial long QT syndrome: An either congenital or acquired abnormality in the cardiac voltage-gated sodium channel (NaV1.5), which is responsible for the rapid upstroke of the myocardial action potential (AP), can cause a potentially life-threatening cardiac disorder, e.g., long QT syndrome (LQTS) or Brugada syndrome (BrS) [10,11].