Genetic polymorphisms of glutathione S-transferase M1 (GSTM1) and T1 (GSTT1) and susceptibility to pre-eclampsia: a case-control study and a meta-analysis

The objective of the present hospital-based case-control study was to assess the association between glutathione S-transferase M1 (GSTM1) and T1 (GSTT1) genetic polymorphisms and susceptibility to pre-eclampsia (PE) in Shiraz (Fars province, southern Iran). A total of 200 healthy pregnant women and 151 pre-eclamptic women were included. The healthy control group was frequency matched with the age of the pre-eclamptic women. Control women had neither PE in current pregnancy nor history of pregnancies with PE previously. The genotypes of GSTT1 and GSTM1 polymorphisms were determined using a PCR-based method. Neither GSTM1 null genotype (OR=1.07, 95 % CI: 0.70-1.64, P=0.736) nor GSTT1 null genotype (OR=0.73, 95 % CI: 0.44-1.21, P=0.233) was associated with risk of PE. Association between combination genotypes and risk of PE was not significant. When family history was entered as a covariate in analysis, adjusted ORs revealed that neither GSTM1 nor GSTT1 polymorphisms was associated with risk of PE. For meta-analysis, we identified 5 eligible studies, including 1217 subjects (515 patients, and 702 healthy controls) in relation to the study polymorphisms and risk of PE. Our present meta-analysis indicated that there neither GSTM1 (OR=0.99, 95 % CI: 0.78-1.25, P=0.955) nor GSTT1 polymorphisms (OR=0.85, 95 % CI: 0.66-1.10, P=0.223) was associated with susceptibility to PE. Taken together it seems that the polymorphisms of GSTM1 and GSTT1 are not risk factors for PE. Further investigations adjusting for confounding factors are needed to confirm the present findings.