Glutathione S-transferase M1 and T1 genotypes and endometriosis risk: a case-controlled study

To investigate the correlation between glutathione S-transferase (GST) M1 and T1 genotypes and endometriosis risk (EM). Polymerase chain reaction (PCR) technique was used to detect the presence or absence of the GSTM1 and GSTT1 genes in genomic DNA isolated from the blood samples of 68 Han Chinese women with endometriosis and 28 without endometriosis. The frequencies of GSTM1 and GSTT1 null genotypes in women with endometriosis were 0.721 (49/68) and 0.779 (53/68), respectively, and in women without endometriosis were 0.429 (12/28) and 0.321 (9/28), respectively. There was a significant difference with regard to the frequencies of GSTM1 and GSTT1 null genotypes between the women with and without endometriosis (P < 0.01). Furthermore, the frequencies of GSTM1 and GSTT1 null genotypes were significantly higher in the patients with stage III and IV endometriosis [0.731 (38/52) and 0.788 (41/52), respectively] than in women without endometriosis (P < 0.01), and the frequency of GSTT1 null genotype was statistically higher in patients with stage I and II endometriosis [0.75 (12/16)] than in the women without endometriosis (P < 0.01). No correlation between GSTM1 and GSTT1 null genotypes and age, induced abortion or dysmenorrhea was detected in this study (P > 0.05). GSTM1 and GSTT1 null genotypes may be risk factors for the development of endometriosis.