Association between DAOA gene polymorphisms and the risk of schizophrenia, bipolar disorder and depressive disorder

• 17,515 cases and 25,189 controls from 46 independent studies were included.
• No significant associations of M15with risks to SCZ, BD and DD were shown.
• No significant associations of M18 with risks to SCZ, BD and DD were shown.
• No significant associations of M23 with risks to SCZ, BD and DD were shown.
• Cumulative meta-analyses by publication year were adopted.

ObjectiveSchizophrenia (SCZ), bipolar disorder (BD) and depressive disorder (DD) are common psychiatric disorders, which show common genetic vulnerability. Previous gene–disease association studies have reported correlations between d-amino acid oxidase activator (DAOA) gene polymorphisms and the three psychiatric disorders. However, the findings were contradictory. A meta-analysis was therefore conducted to provide more robust investigations into DAOA polymorphisms and the risk of SCZ, BD and DD.MethodsThis meta-analysis recruited 46 published studies up to July 2013, including 17,515 cases and 25,189 controls. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to evaluate the association between three specific DAOA SNPs and SCZ, BD and DD. Publication bias was tested by Begg's test and funnel plot, and heterogeneity was assessed by the Cochran's chi-square-based Q statistic and the inconsistency index (I2). Moreover, the robustness of the findings was estimated by cumulative meta-analysis.ResultsDAOA genetic polymorphisms (M15, M18 and M23) were not found to confer a statistically significant increased risk of SCZ, BD or DD in the overall sample, or in Caucasians and Asians following subgroup analysis.ConclusionThe current study indicated that M15, M18 and M23 might not be the risk factor for SCZ, BD or DD. However, further studies are required to provide robust evidence to estimate the association between DAOA polymorphisms and psychiatric disorders.