Glutathione S-transferase M1 and T1 gene polymorphisms in Brazilian women with endometriosis

The glutathione family (GST) genes appear to play a role in the genesis of endometriosis. This case-control study aimed to compare the frequencies of GSTM1 and GSTT1 polymorphisms in women with endometriosis and women without endometriosis. Polymerase chain reaction was performed to analyze the GSTM1 and GSTT1 genotypes among women with surgically and histologically confirmed endometriosis (case group n = 121) and in women without evidence of endometriosis confirmed by laparoscopy for investigation the infertility or for laparoscopic tubal sterilization (control group n = 97). No differences in the frequencies of GSTM1 polymorphism (null genotype) were observed between the cases and controls: odds ratio (OR) = 1.13; 95 % CI 0.656-1.93 (p = 0.659). The GSTT1 polymorphism (null genotype) was more prevalent in the endometriosis group than in the control group (OR = 0.53; 95 % CI 0.94-0.29 (p = 0.039). No relationship between menstrual cycle interval and GSTM1 null genotype frequency was observed in either cases or controls (p = 0.370 and p = 0.664, respectively). In addition, no relationship between menstrual cycle interval and GSTT1 null genotype was observed in cases (p = 0.797) or controls (p = 0.052). GSTM1 null genotype frequency was similar between cases and controls. The GSTT1 null genotype was more frequent in the control group.