RYR2 and catecholaminergic polymorphic ventricular tachycardia: While CALM mutations have been primarily associated with early-onset syndromes such as catecholaminergic polymorphic ventricular tachycardia (CPVT) and long QT syndrome (LQTS) through dysregulation of RyR2 and CaV1.2, recent evidence suggests an expanded phenotypic spectrum [71].