Insertional Variations of Human Endogenous Virus K6 and K11 in Normozoospermic Men.

Male infertility is a multifactorial heterogeneous reproductive disorder in which genetic, epigenetic, and environmental factors play a role in the development of disease. Recent studies have shown that retrotransposon expression alterations may be related to impairment of spermatogenesis. Therefore, in this pilot study, we aimed to investigate whether HERV-K6 and HERV-K11 insertional variations have a role in idiopathic infertility among normozoospermic men. Genomic DNA isolated from the blood samples of 41 infertile normozoospermic and 45 fertile normozoospermic men were analyzed by inter-retrotransposon polymorphism polymerase chain reaction. HERV-K6 variation rates in the infertile and the fertile group were 0-58.3% and 0-53.4%, respectively. The variation rates of HERV-K11 were 0-75.0% in infertile and 0-77.8% in fertile men. The HERV-K6 and HERV-K11 insertion rates of the fertile group were higher than the infertile group (P < 0.0001 and P = 0.007, respectively). The findings of the study suggest that HERV-K6 and HERV-K11 retrotransposon insertion show variation among individuals, and their insertions might be associated with male infertility.