Two variants characterized by diastolic Ca2+ leak inducing DADs are CPVT-1 caused by gain-of-function mutations in RyR2, and CPVT-2 caused by mutations in calsequestrin (CSQ2), the Ca2+ binding protein within the cardiac SR. The gene discussed is RYR2; the disease is catecholaminergic polymorphic ventricular tachycardia 1.