Potassium Voltage Gated Channel Subfamily H, Member 2 (KCNH2)

11.1 potassium ion channel. This ion channel (sometimes simply denoted as 'hERG') is best known for its contribution to the electrical activity of the heart that coordinates the heart's beating (i.e., the hERG channel mediates the repolarizing I_Kr current in the cardiac action potential). When this channel's ability to conduct electrical current across the cell membrane is inhibited or compromised, either by application of drugs or by rare mutations in some families, it can result in a potentially fatal disorder called long QT syndrome; a number of clinically successful drugs in the market have had the tendency to inhibit hERG, and create a concomitant risk of sudden death, as an unwanted side effect, which has made hERG inhibition an important antitarget which must be avoided during drug development