association between insertion/deletion polymorphism in angiotension converting enzyme and susceptibility to schizophrenia.

the activity of angiotension converting enzyme (ace; omim: 106180) in different brain regions of patients with schizophrenia changed, suggesting a possible involvement of ace in psychiatric disorders. genetic polymorphism of insertion/deletion (i/d; dbsnp rs4646994) in the gene encoding ace has been well defined.the present case-control study was performed on 363 (268 males, 95 females) in-patients with schizophrenia diagnosis, and 363 (268 males, 95 females) healthy blood donor controls. the genotypes of i/d ace polymorphism were determined using pcr method. pcr products were separated and sized by electrophoresis on a 2% agarose gel. the insertion allele (i) was detected as a 478 bp band, and the deletion allele (d) was visualized as a 191 bp band. the association between genotypes of the i/d polymorphism and the schizophrenia risk was examined by use of odds ratios (or) and 95% of confidence intervals (cis).among females, the ii genotype significantly decreased the risk of schizophrenia compared with the dd genotype (or=0.18, 95%ci: 0.04-0.72, p=0.015). there was significant linear trend for the number of the i allele and schizophrenia risk among females (chi(2)=5.19, p=0.023). there was no significant association between i/d polymorphism and susceptibility to schizophrenia among male subjects. there was significant interaction between gender and the ii genotype (p=0.031).the ii genotype of the i/d polymorphism has a protective effect for schizophrenia among females.