LQT1 mutations induce a loss of function of Kv7.1, which delays action potential termination and increases the electrocardiogram QT interval longer than 470/480 ms (male/female), thereby increasing the risk of early after discharges (EADs), ventricular arrhythmia, torsades de pointes, seizures, syncope, and sudden death. Here, KCNQ1 is linked to torsades de pointes.