Research Article

Prospective study of MTHFR genetic polymorphisms as a possible etiology of male infertility

Published: March 24, 2014
Genet. Mol. Res. 13 (3) : 6367-6374 DOI: 10.4238/2014.March.24.26

Abstract

The aim of this study was to explore the relationship between 2 genetic polymorphisms of the methylenetetrahydrofolate reductase gene (MTHFR), C677T and A1298C, and determine the long-term reproductive outcome in infertile men. This was a prospective study conducted in an andrology clinic. Men with a 1-year history of infertility were assessed for the MTHFR polymorphisms at a 5-year follow-up. We compared the MTHFR C677T and A1298C polymorphisms by polymerase chain reaction-restriction fragment length polymorphism between men who did and did not bear children during follow-up. Of the 215 men who were infertile at 1 year, 82 (38.1%) remained infertile and 133 (61.9%) achieved natural conception during the 5-year follow-up, with the highest rate in the first year (32.6%). The MTHFR 677TT genotype (homozygote) was associated with a substantially increased risk of infertility during follow-up [odds ratio (OR) = 10.242; 95% confidence interval (CI) = 1.257-83.464] relative to the MTHFR 677CC genotype (wild-type). Risk of infertility was not increased by the MTHFR A1298C polymorphism alone, but was increased by the combination of polymorphisms MTHFR C677T and MTHFR A1298C (OR = 11.818; 95%CI = 1.415-98.674). The homozygous MTHFR C677T genotype was a risk factor for male infertility during 5-year follow-up, whereas a correlation between MTHFR A1298C and infertility was not observed. The MTHFR C677T and MTHFR A1298C polymorphisms had additive effects on male infertility.

The aim of this study was to explore the relationship between 2 genetic polymorphisms of the methylenetetrahydrofolate reductase gene (MTHFR), C677T and A1298C, and determine the long-term reproductive outcome in infertile men. This was a prospective study conducted in an andrology clinic. Men with a 1-year history of infertility were assessed for the MTHFR polymorphisms at a 5-year follow-up. We compared the MTHFR C677T and A1298C polymorphisms by polymerase chain reaction-restriction fragment length polymorphism between men who did and did not bear children during follow-up. Of the 215 men who were infertile at 1 year, 82 (38.1%) remained infertile and 133 (61.9%) achieved natural conception during the 5-year follow-up, with the highest rate in the first year (32.6%). The MTHFR 677TT genotype (homozygote) was associated with a substantially increased risk of infertility during follow-up [odds ratio (OR) = 10.242; 95% confidence interval (CI) = 1.257-83.464] relative to the MTHFR 677CC genotype (wild-type). Risk of infertility was not increased by the MTHFR A1298C polymorphism alone, but was increased by the combination of polymorphisms MTHFR C677T and MTHFR A1298C (OR = 11.818; 95%CI = 1.415-98.674). The homozygous MTHFR C677T genotype was a risk factor for male infertility during 5-year follow-up, whereas a correlation between MTHFR A1298C and infertility was not observed. The MTHFR C677T and MTHFR A1298C polymorphisms had additive effects on male infertility.

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