In our study, we have detected a decrease in the gene expression of CatSper1, CatSper2, CatSper3, CatSpe4, TMEM16A and KCnu1 gene expression by asthenozoospermia patients were detected as lower compared to the controls (p=0.022, p<0.001, p<0.001, p=0.007, p=0.016, p<0.001, respectively) and no significant difference in the other analyzed gene expression. The gene discussed is CATSPER1; the disease is Reduced sperm motility.