Association between methylenetetrahydrofolate reductase C677T polymorphisms and male oligozoospermia, asthenozoospermia or oligoasthenozoospermia: a case-control study.

Mutation of methylenetetrahydrofolate reductase (MTHFR) C677T leads to the decrease of folate utilization and the impairment of spermatogenesis. This study attempts to investigate the association between MTHFR C677T polymorphisms and nonobstructive oligozoospermia, asthenozoospermia or oligoasthenozoospermia in the Chinese population. The study cohort comprised 189 patients diagnosed with oligozoospermia, asthenozoospermia or oligoasthenozoospermia, and 626 controls based on clinical examinations. The MTHFR c.677 genotype of all subjects was determined by fluorescence staining in situ hybridization and the significance of different genotype frequencies was further analyzed by Chi-square test. The results showed that the frequency of MTHFR 677 CT genotype in the oligozoospermia, asthenozoospermia and oligoasthenozoospermia group was 33.3%, 38.3% and 44.0% respectively, whereas it was 47.3% in the control group. The P value of Chi-square test was 0.070, 0.103 and 0.654, respectively. The frequency of MTHFR 677 TT genotype in the oligozoospermia, asthenozoospermia and oligoasthenozoospermia group was 31.1%, 11.7% and 18.0% respectively, while that in the control group was 19.5%. The P value of Chi-square test was 0.061, 0.070 and 0.066, respectively. Collectively, there is a weak association between MTHFR C677T polymorphisms and oligozoospermia, asthenozoospermia or oligoasthenozoospermia within the current Chinese population cohort.