Indeed, variants in the ryanodine receptor 2 (RYR2) gene and the calsequestrin (CASQ2) gene are the main contributors to approximately 60–70% of CPVT, leading to excessive calcium leakage from the sarcoplasmic reticulum and delayed afterdepolarizations and arrhythmias. Here, CASQ2 is linked to catecholaminergic polymorphic ventricular tachycardia.