Two genes, CACNA1C and KCNJ2, were reported to be associated with multiple organ system involvement (Timothy Syndrome and Andersen-Tawil Syndrome, respectively), which include a prolonged QT interval and ventricular arrhythmias as part of the phenotypic expression. The gene discussed is KCNJ2; the disease is Cardiodysrhythmic potassium-sensitive periodic paralysis.