DAOA and bipolar disorder: G72 gene polymorphisms confer susceptibility to schizophrenia13 and bipolar disorder.29, 30, 45 Schizophrenic patients with G72 gene polymorphisms have an elevated level of LG72 protein in the brain and plasma.15, 16 G72Tg mice express G72 transcripts similar to those in humans, including the longest open reading frame, LG72.22 Expression of G72 transcripts was highest in DG,22 a brain area frequently affected in schizophrenia and bipolar disorder (see Introduction).