Association between glutathione S-transferase M1/T1 gene polymorphisms and susceptibility to endometriosis: A systematic review and meta-analysis

Abstract

Endometriosis is a polygenic/multifactorial disease caused by interactions between multiple genes and the environment. Findings from studies evaluating the association between the glutathione S‑transferase (GST) M1/T1 null genotype and susceptibility to endometriosis are inconsistent. This meta‑analysis updated and reevaluated the possible associations between GSTM1, GSTT1 and combined GSTM1/GSTT1 (null genotype versus wild‑type) gene polymorphisms and susceptibility to endometriosis. The PubMed, Embase and Chinese BioMedical Literature databases and Google Scholar were searched for case‑control genetic association studies on GSTM1/GSTT1 (null genotype versus wild‑type) gene polymorphisms and endometriosis in comparison with non‑endometriosis or healthy controls. Fixed‑effect and random‑effect meta‑analytical techniques were conducted for the outcome measure and subgroup analyses. The meta‑analysis demonstrated significant associations between the GSTM1 [odds ratio (OR)=1.56; 95% confidence interval (CI): 1.25‑1.95; P<0.0001), GSTT1 (OR=1.31; 95% CI: 1.02-1.68; P=0.037) and GSTM1/GSTT1 (OR=1.68; 95% CI: 1.29-2.17; P<0.0001) null genotypes and increased risk for endometriosis. The results suggest that the GSTM1, GSTT1, and combined GSTM1/GSTT1 null genotypes increase susceptibility to endometriosis. Additional well-designed studies and precise analyses are warranted to confirm these findings.