Glutathione-S-transferases M1/T1 gene polymorphisms and endometriosis: a meta-analysis in Chinese populations

In view of the controversies surrounding the glutathione-S-transferases (GST) M1/T1-endometriosis association, a meta-analysis of the GSTM1/GSTT1 genetic association studies of endometriosis was performed in Chinese populations. PubMed, Springer Link, OvidSP, and Chinese databases were searched for related studies. A total of nine studies on GSTM1-endometriosis involved 874 cases and 997 controls, and five studies on GSTT1 involved 404 cases and 513 controls were included in this meta-analysis. Overall, the null genotype of GSTM1/GSTT1 was significantly related to endometriosis risk in Chinese populations (GSTM1, OR=2.21, 95% CI: 1.22-4.01; GSTT1, OR=2.31, 95% CI: 1.34-3.99). In subgroup analyses stratified by ethnicity and source of controls, the same results were observed in Chinese Han and population-based studies. The sensitivity analysis confirmed the reliability and stability of the meta-analysis. No publication bias was found among studies by Egger's test. In conclusion, our meta-analysis supports that the GSTM1/GSTT1 null genotype might contribute to individual susceptibility to endometriosis in Chinese populations, especially in Chinese Han.