Genetic variation in the Dlg2 gene, which encodes the membrane associated guanylate kinase (MAGUK) synaptic scaffolding protein PSD93, also known as Dlg2 or chapsyn‐110, has been associated with an array of psychiatric disorders1 including schizophrenia,2 intellectual disability,3 bipolar disorder,4 autism spectrum disorder,5 attention deficit hyperactivity disorder,6 and pubertal disorders.7, 8. The gene discussed is DLG2; the disease is bipolar disorder.