Background: Previous studies indicated that abnormalities in Methylenetetrahydrofolate reductase (MTHFR) may be a risk factor for male infertility, with reduced sperm count. The CpG islands methylation of the MTHFR gene promoter region can be an epigenetic factor involved in protein expression. The aim of this study was to investigate the association of the MTHFR gene promoter methylation with oligospermia men. Methods: In a case-control design, 30 oligospermic and 30 normospermic healthy men were included in our study. Genomic DNA was extracted from the semen samples by general boiling method. The Epitect Bisulfite kit was used for conversion of unmethylated cytosine to thymine in genomic DNA. After bisulfite treatment, MTHFR gene promoter was amplified by methylation specific PCR (MSP) method using specific primers. Result: Our data revealed that the fertile and infertile groups were unmethylated and heterogeneous for the MTHFR promoter region. But the frequency of methylation in infertile men was significantly higher than fertile group (p=0.04). Conclusion: According to the findings, the MTHFR gene promoter can be unmethylated and heterogenous in oligoespermic and normospermic healthy men. But the frequency of MTHFR promoter methylation in infertile men is significantly higher than healthy controls. Therefore, the methylation of MTHFR gene promoter may be an epigenetic risk factor for male infertility which requires more subsequent investigations.
