Analysis of GSTM1, GSTT1, and CYP1A1 in Idiopathic Male Infertility

Enzymes belonging to the glutathione-S-transferase (GST) and cytochrome P450 (CYP) families are involved in a 2-stage detoxification process of a wide range of environmental toxins and carcinogens. In order to investigate whether there is a genetic association of the biotransformation enzymes and idiopathic male fertility, we studied GSTT1, GSTM1, and CYP1A1*2A polymorphisms in 150 infertile men and 200 healthy men as controls from Northern Iran. Genotyping of the GSTT1 and GSTM1 genes were performed using the multiplex polymerase chain reaction (PCR). However, the CYP1A1 polymorphism was determined using PCR-restriction fragment length polymorphism (RFLP). The GSTM1 and GSTT1 null genotypes were present at frequencies of 0.61 and 0.34 in infertile cases, whereas in controls the frequencies were 0.33 and 0.17, respectively. Double-null genotype was found to be elevated among infertile men (odds ratio [OR] - 3.75, 95% confidence interval [CI] - 2.42-6.45; P <.0001). The frequency of TT, TC, and CC genotypes of CYP1A1 polymorphism in the controls were 42.5%, 45.5%, and 12%, respectively, while those in the infertile men were 38.7%, 48%, and 13.3%. The CYP1A1*2A did not display any association with male infertility. We observed an association between male infertility and the GSTM1 and GSTT1 null deletion, but not with the CYP1A1 polymorphism in North Iranian men with idiopathic infertility.