KCNJ2 and Cardiodysrhythmic potassium-sensitive periodic paralysis: Citing its relationship to other disorders of myocellular repolarization, predisposition to ventricular arrhythmias,  and the purported presence of a prolonged QT interval in 71% of all KCNJ2 mutation carriers, it had been suggested that ATS be classified as LQT7 [8].