In another Japanese study by Aizawa et al., 83 Japanese patients with idiopathic ventricular fibrillation, LQTS, BrS, CPVT, or arrhythmogenic right ventricular cardiomyopathy underwent genetic testing of RYR2 to find disease-causing variants (77). This evidence concerns the gene RYR2 and catecholaminergic polymorphic ventricular tachycardia.