Patients with vasal agenesis or unexplained obstructive azoospermia and low semen volume should be tested for abnormalities of the cystic fibrosis transmembrane conductance regulator (CFTR) gene.
The results militate against the assumption that there is an association between the CFTR gene and unilateral aplasia of vas deferens or bilateral aplasia of vas deferens with renal involvement.
A higher prevalence of cystic fibrosis transmembrane regulator (CFTR) gene mutations has been suggested both in men affected by congenital aplasia of the vas deferens, and in individuals presenting with reduced sperm quality.