Similarly, although the phenotype most frequently shown by patients with CALM pathogenic variants is LQTS, others display CPVT and sudden unexplained death and some CALM variants have been associated with both LQTS and CPVT, without evidence of distinct mechanisms underlying different phenotypic manifestations [49, 52]. Here, CALM2 is linked to catecholaminergic polymorphic ventricular tachycardia.