Involvement of CFTR gene alterations in obstructive and nonobstructive infertility in men.

There have not been many studies concerning CFTR gene alterations in nonobstructive causes of male infertility and subfertility, and in those that have been published, the results reported are not concordant. Therefore, we proposed to determine, in a representative unselected sample of men who were sent for microsurgical epididymal sperm aspiration, if different types of male infertility and impaired fertility were associated with CFTR gene alterations. We screened 80 men with idiopathic azoospermia, 50 men with severe oligozoospermia, 70 men with oligoasthenoteratozoospermia, and 7 men with congenital bilateral absence of the vas deferens (CBAVD), as well as 95 controls from Slovenia, for mutations in 10 CFTR exons that include the majority of the most common cystic fibrosis (CF) disease causing mutations. We also wanted to evaluate the risk for CF in children born after the intracytoplasmic sperm injection (ICSI) method of in vitro fertilization (IVF). No tested individual had mutations in both CFTR alleles. Altogether 13 different nucleotide alterations were identified. The frequencies of both CFTR gene alterations and polymorphisms did not differ significantly between the control group and men with idiopathic nonobstructive azoospermia and subfertility, but were significantly increased in men with CBAVD (DeltaF508, p = 0.039; IVS8-5T, p = 0.006). Our results suggest that CFTR mutations are not associated with errors in spermatogenesis and nonobstructive pathology of urogenital tract in men with any frequency. However, genetic counseling and CFTR mutation screening continue to be recommended for men with obstructive azoospermic conditions and their female partners.