While multiple mutations have been implicated in the pathogenesis of LQTS, KCNQ1 (LQT1), KCNH2 (LQT2), and SCN5A (LQT3) are the most common LQTS gene mutations, accounting for approximately 90% of all genotype-positive cases [4]. The gene discussed is KCNQ1; the disease is familial long QT syndrome.