RYR2 and catecholaminergic polymorphic ventricular tachycardia 1: Subtype 1 (CPVT1) is generated by gene mutations on the ryanodine receptor Type 2 gene (RYR2), while a mutated calsquestrin-2 (CASQ2) gene is responsible for subtype 2 (CPVT2) [167].