Polymorphisms of estrogen receptors alpha and beta in idiopathic, infertile Brazilian men: a case-control study.

Estrogen plays an important role in the human reproductive system and its action is mediated mainly by two specific receptors: α (ERα) and β (ERβ). There are polymorphic variants in both ER genes, and studies showed their association with reproductive outcomes. We aimed to determine the distribution of ERα and ERβ gene polymorphisms in idiopathic, infertile Brazilian patients in a case-control study comprising 187 idiopathic, infertile Brazilian men with nonobstructive azoospermia (NOA, n = 78) or severe oligozoospermia (SO, n = 109) and 216 fertile men.