CASQ2 and catecholaminergic polymorphic ventricular tachycardia: Importantly, since RYR2 and CASQ2 variants are identified in around 60% of CPVT cases [12,93], and the background rate of rare benign variation in RYR2 approaches 3% [94,95], genetic testing should not be used to rule out the diagnosis when clinical suspicion exists or rule it in when the variant is not definitively pathogenic.