RYR1 and catecholaminergic polymorphic ventricular tachycardia: An isoform-specific effect on RyR structure was revealed by evaluating the effect of the RyR2-R176Q mutant involved in CPVT and ARVD2, and its homologous the skeletal muscle RyR1-R163C, implicated in malignant hyperthermia (MH) and central core disease.