Monoamine oxidase A gene polymorphism and suicide: An association study and meta-analysis

Background: Abnormalities in brain monoamine transmission have been implicated in the pathogenesis of suicidal behavior. Studies examining the association between monoamine oxidase A (MAOA)-uVNTR polymorphism and suicide revealed inconsistent findings. This study aims to evaluate the possible association between the MAOA-uVNTR polymorphism and suicidal behaviors by examining our own subjects and conducting a meta-analytic review. Methods: 373 unrelated psychiatric patients (including 160 suicide attempters and 213 non-suicide attempters) were genotyped for the MAOA-uVNTR polymorphism. A meta-analysis was then performed by pooling data from seven case-control association studies by random effects model. Results: Our results indicate that there is no association between the MAOA-uVNTR polymorphism and suicide attempts in both genders. It also reveals that there is no association with violent suicide attempts. In the meta-analysis, there is no association between the polymorphism and suicidal behaviors. Also, there is no difference in the allelic distribution between psychiatric patients with and without suicidal behaviors. Limitations Our study was constrained by the insufficient information about environmental risk factors of suicide. Conclusions: Our study is the first one to use meta-analysis in exploring the role of the MAOA-uVNTR polymorphism in suicidal behavior in psychiatric patients. No significant association was found in our study, suggesting MAOA-uVNTR polymorphism is unlikely to contribute significantly to suicide behavior. Further studies investigating the gene-environment interaction or focusing on the genetic risk factors of endophenotypes of suicidal behaviors are warranted.