CNVs involving single or multiple exons of the major channelopathy genes, KCNQ1, KCNH2, SCN5A, and RYR2, uncommonly serve as the pathogenic basis of dominantly inherited arrhythmia syndromes such as long QT syndrome, Brugada syndrome, and CPVT (3, 8, 9, 11, 17–19). The gene discussed is SCN5A; the disease is catecholaminergic polymorphic ventricular tachycardia.