The c.-190 C > A transversion in promoter region of protamine1 gene as a genetic risk factor for idiopathic oligozoospermia

Abstract

The genome condensation in the sperm head is resulted with replacing of histones by protamines during spermatogenesis. It is reported that defects in the protamine 1 (PRM1) and/or 2 (PRM2) genes cause male infertility. Located on chromosome 16 (16p13.2) these genes contain numerous unstudied single nucleotide polymorphisms. This study aimed to investigate the association of c.-190 C > A and g.298 G > C transversions that respectively occur in PRM1 and PRM2 genes with idiopathic oligozoospermia. In a case-control study, we collected blood samples from 130 idiopathic oligozoospermia and 130 fertile men. Detection of c.-190 C > A and g.298 G > C polymorphisms performed by direct sequencing and PCR-RFLP methods respectively. An in silico analysis was performed by ASSP, NetGene 2, and PNImodeler online web servers. Our data revealed that g.298 G > C transversion in PRM2 was not associated with oligozoospermia (P > 0.05). Whereas, -190CA and -190AA genotypes in PRM1 gene were associated significantly with increased risk of oligozoospermia (P = 0.0017 and 0.0103, respectively). Also carriers of A allele (CA+AA) for PRM1 c.-190 C > A were at a high risk for oligozoospermia (OR 3.2440, 95 % CI 1.8060-5.8270, P = 0.0001). Further, in silico analysis revealed that c.-190 C > A transversion may alter transcription factor interactions with the promoter region of PRM1. The results revealed that the c.-190 C > A transversion may involve in the susceptibility for oligozoospermia and could be represented as a noninvasive molecular marker for genetic diagnosis of idiopathic oligozoospermia.