Introduction & Objective: Infertility affects 10-15% of couples worldwide, and male factors account for nearly half of all infertility cases. Evidence suggests that genetic variation in anti-oxidant enzymes could influence male infertility. Glutathione peroxidase 1 (GPx1) is an anti-oxidant selenoenzyme that detoxify peroxide radicals. GPx1 Pro198Leu polymorphism causes an aminoacid change from Pro to Leu at codon 198, with the Leu variants being less active than its Pro counterpart. The aim of this study was to determine the association between GPx1 Pro198Leu polymorphism and idiopathic male infertility.

 Materials & Methods: The case – control study comprised of two groups: 100 infertile patients and 120 fertile healthy control men. Genotyping was carried out by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) using ApaI endonuclease. Chi-square test was applied for statistical comparison of genotype data. 

Results: The prevalence of genotype frequencies of the GPx1 gene Pro/Pro, Pro/Leu, Leu/Leu were 13%, 76%, 11% in infertile male, respectively, while in the control were 24.17%, 67.5%, 8.33%, respectively. Allele frequencies of the GPx1 gene Pro, Leu were 0.51, 0.49 in infertile male, while in the control were 0.58 and 0.42, respectively. No significant differences between cases and controls were found in the allelic and genotype distribution of the GPx1 Pro198Leu polymorphism (P>0.05). 

Conclusion: In conclusion, the overall results of the study indicate that GPx1 Pro198Leu poly-morphism is not associated with idiopathic male infertility. However, further research is re-quired to clarify the role of GPx1 gene in idiopathic male infertility.