Objective: To investigate the correlation of the single nucleotide polymorphisms rs995030 and rs4474514 of the tyrosine kinase receptor-specific ligand (KITLG) gene with the risk of male infertility.
Methods: This study included 360 patients with idiopathic male infertility and 338 healthy fathers as controls, all from the surrounding areas of Nanjing. According to the 5th edition of the WHO Laboratory Manual for the Examination and Processing of Human Semen, we divided the infertility patients into an azoospermia (n = 143), a severe oligozoospermia (n = 159), and an oligozoospermia group (n = 58). We obtained the basic clinical data on all the subjects, collected genomic DNA from the peripheral blood of the patients, determined the genotypes of the KITLG gene rs995030 and rs4474514 by sequence mass-array, and analyzed the correlation between the two-point gene polymorphism and male infertility by logistic regression analysis.
Results: Statistically significant differences were observed between the infertility patients and normal fertile controls in sperm concentration (［13.23 ± 24.52］ vs ［78.74 ± 61.25］ ×10⁶/ml, P < 0.01), the percentage of progressively mobile sperm (［18.71 ± 15.19］% vs ［39.36 ± 9.75］%, P < 0.01), and the level of FSH (［16.09 ± 17.31］ vs ［4.56 ± 2.41］ IU/L, P < 0.01), but not between the genotypes and male infertility, and no correlation was found in subgroup analysis.
Conclusions: The single nucleotide polymorphisms rs995030 and rs4474514 of the KITLG gene were not significantly correlated with male infertility, which is to be further verified by more studies with samples of larger size and expanded selection range.
Keywords: male infertility; nucleotide polymorphism; rs4474514; rs995030; tyrosine kinase receptor-specific ligand gene.