Genetics
Loss of function mutations in this channel may lead to long QT syndrome (LQT2), while gain of function mutations may lead to short QT syndrome. Both clinical disorders stem from ion channel dysfunction (so-called channelopathies) that can lead to the risk of potentially fatal cardiac arrhythmias (e.g., torsades de pointes), due to repolarization disturbances of the cardiac action potential. There are far more hERG mutations described for long QT syndrome than for short QT syndrome.
Read more about this topic: HERG