Methylenetetrahydrofolate reductase polymorphisms are related to male infertility in Brazilian men.

Objective: The objective of this study was to analyze the distribution of the methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C polymorphisms in idiopathic infertile Brazilian patients with nonobstructive azoospermia (NOA) or severe oligozoospermia and fertile Brazilian men as controls to explore the possible association of these polymorphisms and male infertility.

Methods: A case-control study was carried out, including 156 idiopathic infertile Brazilian patients with NOA (n=49) or severe oligozoospermia (n=107) and 233 fertile men as controls. Polymorphisms C677T and A1298C were studied by quantitative polymerase chain reaction and the results were statistically analyzed.

Results: The frequency of genotypes MTHFR 677CC, 677CT, and 677TT in idiopathic infertile men with NOA were 55.1%, 30.6%, and 14.3% (p=0.0305); 50.6%, 42.0%, and 7.5% (p=0.0006) regarding the severe oligozoospermic men; and 71.7%, 53.0%, and 5.6% in the control group. As for polymorphism A1298C, regarding the NOA group, the frequencies of the 1298AA, 1298AC, and 1298CC genotypes were 53.0%, 28.6%, and 18.4% (p=0.0132); 42.0%, 44.9%, and 13.1% (p=0.0188) among the severe oligozoospermic group; and 55.8%, 38.2%, and 6.0% (14/233) in the control group.

Conclusion: The data suggest that MTHFR C677T and A1298C could be important genetic factors predisposing to infertility in Brazilian infertile men.