Angiotensin converting enzyme gene insertion/deletion polymorphism: Case-control association studies in schizophrenia, major affective disorder, and tardive dyskinesia and a family-based association study in schizophrenia

Angiotensin converting enzyme (ACE) is a candidate gene for psychiatric disorders. We examined the frequency of a functional insertion/deletion (I/D) polymorphism in the 16th intron of the ACE gene (located on chromosome 17q23) in groups of patients with schizophrenia (n = 104 and 113), major depression (n=55), and bipolar disorder (n=87) compared to healthy control subjects (n=87). There was no evidence for allelic or genotypic association of the polymorphism with any of the disorders or with tardive dyskinesia (TD) in patients with schizophrenia. In a sample of nuclear families (n = 61) made up of one or more patients with schizophrenia recruited with their parents, there was no evidence for biased transmission of ACE I/D alleles. Particularly in the case of schizophrenia, these findings do not support an association of the ACE I/D polymorphism with the phenotypes examined.