Genetic factors cause various forms of male infertility in 30–50% of cases. The role of oxidative stress in male infertility has been broadly recognised, and the search for a new marker to determine the redox environment in semen has gained considerable interest.
Aim: to establish the association of two polymorphic loci Ile105Val, Ala114Val of the GSTP1 gene (glutathione transferase class pi-1) with the parameters of oxidative stress in men with infertility.
Materials and methods: the main study group consisted of 160 men of reproductive age with infertility (mean age – 29,9±5,3 years). The control group included 104 practically healthy men with realized reproductive function (average age – 30,2±3,6 years). Molecular and genetic study of polymorphisms of the GSTP1 gene was performed by using real-time PCR. The material for the study was DNA samples, the extraction of which was carried out from samples of whole venous blood. The components of lipid peroxidation and antioxidant protection were determined in the blood and ejaculate using spectrophotofluorometric
methods.
Resalts: While analyzing the frequency of occurrence of the Ile105Val polymorphism of the GSTP1 gene in men with infertility and fertile men, statistically significant differences were found at (χ2=7,487; p=0,024). No significant differences were found between the groups (χ2=3,823; p=0,14), when were compared the frequency distribution of the genotypes of the Ala114Val polymorphism of the GSTP1 gene in men diagnosed with infertility and fertile patients. In men with infertility, carriers of the GSTP1(Ile105Val) heterozygous polymorphism, associations of the studied gene were established with an increase in GSH activity by 7% and a decrease in GR by 20% in blood and a decrease in SOD activity by 8% in the ejaculate, in contrast, fertile men, carriers of heterozygous polymorphism GSTP1(Ile105Val), which have associations with an increase in total AOA blood by 20% and with a decrease in GPO activity by 24% in the ejaculate. In men with infertility, carriers of the heterozygous polymorphism of GSTP1(Ala114Val), associations of the studied gene were established with a decrease in α-tocopherol concentration by 15%, an increase in GPO activity by 25% in blood and a decrease in SOD activity by 7% in ejaculate, in contrast, fertile men, carriers of heterozygous polymorphism GSTP1(Аlа114Val), which have associations with an increase in the concentration of DK in blood by 19% and with a decrease in GST activity by 32% in the ejaculate.
Conclusion: identification of carriers of polymorphic loci Ile105Val, Ala114Val GSTP1, as well as determination of enzymes of the thiol disulfide system can be recommended for additional assessment of the risk of reproductive disorders in men.

Keywords: man, infertility, gene polymorphism, oxidative stress