Synergistic effect of androgen receptor (CAG repeat length) and endothelial nitric oxide synthase (Glu298Asp variant) gene polymorphisms on seminal parameters in men with idiopathic oligoasthenozoospermia

摘要

Genetics play an important role in the multi-factorial aetiology of male infertility. In fact, some evidence suggests that both the androgen receptor (AR) gene and endothelial nitric oxide synthase (eNOS) gene are involved in this disease. Usually, the polymorphic length of AR CAG tract correlates inversely with receptor activity in various tissues [1]. However, the role of this polymorphism in male infertility is more complex, as amply proven by the inconsistent findings [2-4]. On the other hand, an association has been found between male infertility and the presence of the Glu298Asp single nucleotide polymorphism (SNP) of the eNOS gene [5]. The subsequent con-formational change of eNOS protein structure and/or function with consequent nitric oxide (NO) hyperproduc-tion could result in a negative influence on sperm function [5, 6] even if a recent study did not confirm this association.