CACNA1D and attention deficit-hyperactivity disorder: In addition to the cardiac phenotype observed in SANDD, heterozygous CACNA1D mutations also cause high risk for a broad neurodevelopmental disease spectrum, including childhood epilepsy, autism spectrum disorders (A769G, G407R, V401L, Q567H, V1482L) [24,25,37,38], attention deficit hyperactivity disorder-like symptoms (S672L) [23], as well as primary hyperaldosteronism (I770M, G403D, A769T, V259D) [26,39,40] and congenital hypoglycemic hyperinsulinemia (G403D) [41].