Agenesis of vas deferens and cystic fibrosis

Congenital bilateral absence of vasa deferens appears in 6% of obstructive azoospermia, and 60-70% of these patients also have cystic fibrosis mutations. Unilateral aplasia or agenesia of vasa deferens occurs in less than 1% male individuals and some studies have found that up to 43% cases show mutations in the cystic fibrosis gen. We contribute four case reports of bilateral agenesia who were seen for infertility, all of which showed presence of mutation. In none of the two cases of unilateral agenesia, who consulted for vasectomy, a mutation in the cystic fibrosis gen was found. Patients with bilateral agenesia and their partners should be screened for cystic fibrosis, prior to spermatic microaspiration and assisted fecundation.