Current-centric classification of long-QT syndrome susceptibility genes^[1]

The clinical phenotypes resulting from the abnormal ventricular cardiac action potential depolarization or repolarization are grouped according to the specific current perturbed by an underlying genetic defect (refer to graphic’s key, above). The graphic shows both mutations that confer a loss of function to the specified current and mutations that confer a gain of function (refer to graphic’s key, above). Solid lines indicate those disorders that are autosomal dominant, whereas dashed lines indicate those disorders that are autosomal recessive. Thin outlines indicate nonsyndromic genotypes and thick outlines represent multisystem genotypes.