Although structural cardiovascular abnormalities explain most cases of sudden cardiac death in young people, the cause of death remains unexplained after autopsy in 10% to 30% of cases. Potentially lethal ion channel disorders (channelopathies) such as the long QT syndromes (LQTS), catecholaminergic polymorphic ventricular tachycardia (CPVT), and the Brugada syndrome (BrS) may account for at least one-third of these unexplained cases.