SMITten for KCNQ Channels

Over the last two decades, members of the KCNQ channel family of potassium channels (KCNQ1–5) have emerged as critical regulators of cardiac and neuronal excitability (1,2). KCNQ1 channels are the molecular determinants of the cardiac slow potassium current, IKS (1), which is partly responsible for the repolarization of the cardiac action potential. Loss-of-function variants of KCNQ1 channels lead to a rare heart condition, long QT syndrome, and gain-of-function variants lead to atrial fibrillation.