Endometriosis is one of the most common and benign gynecologic disorders which lead to infertility in women. It is characterized by stroma and ectopic growth of endometrial tissue outside uterus cavity. Glutathione S-transferase M1 (GSTM1) and Glutathione S-transferase T1 (GSTT1) null genotypes have been suggested to be associated with endometriosis by many epidemiological studies. The aim of this study was to investigate whether the polymorphisms and null genotypes are associated with the susceptibility to endometriosis in Asian populations. We investigated GST genes polymorphisms in a large sample size case-control study, and conducted a literature-based meta-analysis. Relevant studies for inclusion were identified after preliminary investigation of research papers published on electronic databases up to February 2016. A total of 13 case–control studies were selected. Data analysis was performed using Comprehensive Meta-Analysis package, version 2. Pooled odds ratios (ORs) with 95% confidence intervals (95% CIs) were calculated by comparing the null genotype with other genotypes using the fixed-effects model. Overall, the null genotype of GSTM1 and GSTT1 was significantly related to endometriosis risk in Asian populations. This findings suggest that the GSTM1 and GSTT1 predisposes Asian populations to endometriosis. Further investigations are required to confirm these findings.
