In conclusion, this meta-analysis is in favor that the MTHFRC677T polymorphism is capable of causing male infertility susceptibility, especially in Asians and the subgroup of azoospermia.
Our meta-analysis showed that the MTHFRC677T mutation was a risk factor for male infertility in both azoospermia and oligoasthenoteratozoospermia patients, especially in Asian population.
Genetic association study revealed a significant association of MTHFR-222Val/Val genotype with oligozoospermia (OR 2.32; 95% CI, 1.12 to 4.78; P = 0.0451) and azoospermia (OR 2.59; 95% CI 1.09 to 6.17; P = 0.0314).
In conclusion, this meta-analysis supports that the MTHFRA1298C polymorphism is capable of causing male infertility susceptibility, especially azoospermia.
Single nucleotide polymorphism C677T in the methylenetetrahydrofolate reductase gene might be a genetic risk factor for infertility for Chinese men with azoospermia or severe oligozoospermia.
By classifying 360 infertile patients into 174 azoospermia and 186 oligoasthenoteratozoospermia (OAT) subjects, the MTHFR 677TT and MS 2756GG types were significantly associated with the azoospermia group (P = 0.0227 and 0.0063, respectively).