RESUMO
PURPOSE: 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. METHODS: 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). RESULT(S): 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). CONCLUSIONS: GSTM1 null genotype frequency was similar between cases and controls. The GSTT1 null genotype was more frequent in the control group.