KCNH2 and familial long QT syndrome: Early genetic linkage analysis studies successfully identified many of the major genes involved in the pathogeneses of these disorders, including: KCNQ1 (OMIM: 607542), KCNH2 (OMIM: 152427), and SCN5A (OMIM: 600163) in LQTS [5,6,7,8]; SCN5A in BrS [9], MYH7 (OMIM: 160760), and MYBPC3 (OMIM: 600958) in HCM [10,11]; and PKP2 (OMIM: 602861) in arrhythmogenic right ventricular cardiomyopathy (ARVC)/ACM [10,11,12].