Loss- or gain-of-function mutations in the CACNA1C gene, encoding the α1C (Cav1.2) L-type Ca2+ channel subunit, are associated with a pleiotropic set of disorders including the autism spectrum disorder (ASD) Timothy Syndrome, bipolar disorder, schizophrenia, and major depressive disorder (MDD), as well as severe cardiac defects 63–68. Here, CACNA1C is linked to major depressive disorder.