CACNA1C and catecholaminergic polymorphic ventricular tachycardia: [24, 25] In our cohort, subject #14 carried a CACNA1C VUS and a pathogenic RYR2 mutation (plus several other RYR2 VUS), and had a classic CPVT phenotype (catecholamine triggered bidirectional VT) with some QT prolongation.