Association between COMT gene rs165599 SNP and schizophrenia: A meta‐analysis of case‐control studies

BACKGROUND: There are many studies with different results that examine the association between Catechol‐O‐MethylTransferase (COMT) gene single‐nucleotide polymorphisms (SNPs) and schizophrenia. In this study, the aim was to conduct a meta‐analysis to achieve a pooled effect size of the association between COMT gene rs165599 SNP and schizophrenia. METHODS: Odds ratio (OR) was used as an effect size to determine the association between schizophrenia and the SNP. The pooled ORs were achieved under four different genetic models. When the heterogeneity among studies was high the DerSimonian‐Laird random‐effects model, otherwise the Mantel‐Haenszel fixed‐effects model was used. Publication bias was evaluated by Egger's test. RESULTS: Under different genetic models no statistically significant association was found between rs165599 SNP and schizophrenia by meta‐analyses consist of 20 independent studies. There was high heterogeneity among studies, for the possible reason the population differences, although the subgroup analyzes reduced the heterogeneity, no association was obtained. However, the sex‐specific estimation of the females showed that to be a G allele carrier is a risk factor for schizophrenia (OR = 1.366 [95% confidence interval = 1.094–1.706]) compared to AA homozygous. CONCLUSION: The COMT gene rs165599 SNP does not appear to be a single‐risk factor for schizophrenia.