KCNJ2 and catecholaminergic polymorphic ventricular tachycardia: Several publications support the fact that pathogenic variants in KCNQ1, ANK2, KCNE1, KCNE2, KCNH2, KCNJ2 and SCN5A can lead to a complex overlapping phenotype of LQTS, CPVT and ventricular ectopy [42,48,92].