Influence of the XbaI polymorphism in the estrogen receptor-α gene on human spermatogenic defects.

Polymorphisms of estrogen receptor (ER) genes have been implicated in male infertility, but studies of this association have produced conflicting results. The present study was conducted to examine whether polymorphisms within the ERα and ERβ genes are susceptibility factors for human male idiopathic infertility in Chinese men. We investigated the association between the ERα gene gene and PvuII and XbaI polymorphisms and the ERβ gene and RsaI and AluI polymorphisms and idiopathic male infertility in Han Chinese men. A total of 204 men with oligozoospermia (sperm count <20 x 10(6)/mL) or azoospermia and 252 fertile control men were included in this study. The analysis revealed a strong association between the XbaI genotype distribution and impaired spermatogenesis (P = 0.0018). The frequency of the G allele was significantly lower in patients than in controls (P = 0.003). Furthermore, serum levels of follicle-stimulating hormone and luteinizing hormone in XbaI AA carriers were significantly higher than those in AG or GG carriers. Our findings further support a possible role of ERα in male infertility. Further studies are needed to replicate our findings, as well as to elucidate more fully the biological mechanisms of the modulation of ERα on human spermatogenesis.