KCNH2 and familial long QT syndrome: Notably, some genes that cause LQTS are the same genes that also cause SQTS (KCNQ1, KCNH2, KCNJ2, CACNA1C, CACNB2, and CACNA2D1), CPVT (CALM1, CALM2, CALM3, TRDN, KCNJ2, SCN5A, ANK2 and TECRL) or BrS (SCN5A) [42,89].