Although genetic heterogeneity is observed in LQTS, KCNQ1 (LQTS1) and KCNH2 (LQTS2), both encoding potassium channel proteins, and SCN5A (LQTS3), encoding a sodium channel protein, are the most common genes responsible for LQTS [1, 2]. Here, KCNQ5 is linked to familial long QT syndrome.