Association between male infertility and genetic variability at the PON1/2 and GSTM1/T1 gene loci

Environmental xenobiotics such as organophosphate pesticides are known factors involved in male infertility. Paraoxanase (PON) and glutathione transferase (GST) are involved in biotransformation of organophosphate pesticides. Interindividual genetic variations in biotransformation enzyme activities can lead to differences in the susceptibility to male infertility. This case-control study investigated associations between polymorphisms in the PON and GST genes (PON1-55/192, PON2-311, GSTM1/T1) and infertility. The study group consisted of 187 infertile men (86 with non-obstructive azoospermia (NOA) and 101 with oligoasthenoteratozoospermia (OAT)), whereas the control group comprised of 194 fertile men. Statistically significant differences were found in PON1-55MM genotype (chi-squared=7.37; P=0.02) and PON1-55M allele (chi-squared=5.98; P=0.01) distribution between the infertile and fertile men. A separate analysis revealed that significant differences in genotype frequencies were limited to the OAT group (chi-squared=9.11, P=0.01). However, no significant differences in genotype frequencies of other tested polymorphisms (PON1-192, PON2-311, GSTM1/T1) and male infertility were observed. The PON1-55M allele might represent a risk factor for infertility susceptibility in Slovenian men. Further studies with a larger sample size are needed to confirm these findings.