Analysis of MLH3 C2531T Polymorphism in Infertile Men with Idiopathic Azoospermia or Severe Oligozoospermia

Infertility is described as the inability to get pregnant after one year of unprotected intercourse. About half of infertility cases are because of male factors. Idiopathic azoospermia or severe oligozoospermia caused by genetic alterations is a significant part of male infertility. A key step of spermatogenesis is crossover events during meiotic reciprocal recombination. MLH3 protein has a crucial role in meiotic recombination and in spermatogenesis. We evaluated this function of MLH3 protein by examining the contribution of functional polymorphism in MLH3 (C2531T) to the risk of male infertility.

We studied this polymorphism in 110 infertile male with idiopathic azoospermia or severe oligozoospermia, and 110 fertile men with normozoospermia as a control group. MLH3 C2531T polymorphism was analyzed using the tetra-amplification refractory mutation system-PCR (4P-ARMS-PCR) method.

Genotypes CC, CT and TT of the MLH3 gene presented frequencies of 13.6%,59.1% and 27.3%, respectively, in the men with idiopathic azoospermia or severe oligozoospermia and 37.3%,53.6% and 9.1% in the control group (p<0.001).

The data suggest that the MLH3 C2531T polymorphism can be associated with risk of male infertility. The research data showed that presence of the polymorphic allele T leads to an increased risk of 2.35 times (OR =2.35, 95% CI =1.57-3.51; p<0.001) to develop infertility in relation to the normal control group. Therefore, the MLH3 gene polymorphism may be genetic determinant for defective spermatogenesis in the humans.