The association of testis-specific hTAF7L gene variants with idiopathic azoospermic and severe oligozoospermic male infertility

Spermatogenesis is regulated by complex tissue specific gene expression in the testis to achieve normal male fertility. X-chromosome specific TATA binding protein (TBP)-associated factor 7L (hTAF7L) is one of the transcriptional regulator genes considered essential for spermatogenesis. The aim of this study was to evaluate the role of variants/mutations in the testis-specific hTAF7L gene in non-obstructive azoospermia and severe oligozoospermia male infertility. We studied 156 idiopathic non-obstructive azoospermic, severe oligozoospermic infertile males and 50 fertile proven controls. Infertile males and control subjects were genotyped for variants of the hTAF7L gene using polymerase chain reaction and a direct Sanger sequencing approach. The odds ratio evaluated the association of hTAF7L gene variants with idiopathic male infertility. The variants found in the hTAF7L gene were subjected to an in-silico analysis study. In infertile study subjects, we observed 11 single base pair nucleotide changes at various exons and three frameshift variants at exon 10 in the hTAF7L gene. We also found more than one variant in some non-obstructive azoospermia and severe oligozoospermia infertile males along with control subjects. All these variants changed the amino acid sequences in the hTAF7L gene. However, similar changes were also seen in fertile subjects, and the differences were not statistically significant. In-silico tools also predicted that the variants were likely to be benign. The variants in cDNA of the hTAF7L gene were typical SNPs. It is found that the hTAF7L gene is highly polymorphic and these missense variants are not directly associated with male infertility. However, we feel that more studies are needed to elucidate the role of multiple variants of the hTAF7L gene in the process of normal spermatogenesis.