The CaM-N98S mutation was found in CALM1 in one individual, and in three other individuals in CALM2. Interestingly, these four patients present with different phenotypes – either CPVT or LQTS or both – suggesting that we still do not fully understand the underlying mechanisms determining the disease phenotype. Here, CALM3 is linked to catecholaminergic polymorphic ventricular tachycardia.