Congenital absence of the vas deferens (CAVD) is a condition in which the vasa deferentia reproductive organs fail to form properly prior to birth.
The mutational spectrum of CFTR in the first group differs from that observed in classic cystic fibrosis, with milder missense or splice variants present on at least one chromosome.
In the subset of males with both CBAVD and URA, the CFTR mutation has been shown to occur at a rate only slightly higher than the overall population.
[7][8] Mutation of the CFTR gene is found to result in obstructive azoospermia in postpubertal males with cystic fibrosis.
Strikingly, CAVD is one of the most consistent features of cystic fibrosis as it affects 98-99% of individuals in this CF patient population.