This first report of Kv1.5 loss-of-function channelopathy establishes KCNA5 mutation as a novel risk factor for repolarization deficiency and atrial fibrillation.
Rare mutations in KCNH2 provide the pathogenic substrate for type 2 congenital long QT syndrome (LQTS), thus placing this cardiac potassium channel squarely in the intersection between congenital LQTS (the "Rosetta stone" of the heritable channelopathies) and acquired LQTS (drug-induced TdP).