Congenital bilateral absence of vas deferens

What is congenital bilateral absence of vas deferens?

Congenital bilateral absence of vas deferens occurs in males when the tubes that carry sperm from the testes (the vas deferens) fail to develop normally. This condition can occur alone or as a sign of cystic fibrosis, an inherited disease of the mucus glands.

Men with congenital bilateral absence of vas deferens are unable to conceive a child (infertile). The testes usually develop and function normally and affected men have normal sexual performance, but sperm cannot be transported through the male reproductive system.

When this condition occurs in the absence of typical cystic fibrosis, most men do not have any of the other health problems associated with that disease (such as progressive lung damage and chronic digestive system problems). Some men with the disorder have mild respiratory or digestive symptoms, however.

How common is congenital bilateral absence of vas deferens?

This condition is responsible for 2 percent to 5 percent of all infertility in men.

What genes are related to congenital bilateral absence of vas deferens?

Mutations in the CFTR gene cause congenital bilateral absence of vas deferens.

More than half of all men with this condition have mutations in the CFTR gene. Mutations in this gene also cause cystic fibrosis. When congenital bilateral absence of vas deferens occurs with CFTR mutations, it is considered to be a form of atypical cystic fibrosis.

The protein made by the CFTR gene forms a channel that controls the movement of salt and water into and out of cells. Mutations in the CFTR gene alter this protein in such a way that the channel is blocked. As a result, cells in the male genital tract produce an abnormally thick, sticky mucus that obstructs the developing vas deferens and causes it to degenerate.

When there is no mutation in the CFTR gene, the cause of this disorder is often unknown. Some cases are associated with other structural problems of the urinary tract.

How do people inherit congenital bilateral absence of vas deferens?

When this condition is caused by mutations in the CFTR gene, it is inherited in an autosomal recessive pattern. This means that two copies of the gene in each cell must be altered for a person to be affected by the disorder. If men with this disorder choose to undergo assisted reproduction, they are at an increased risk of having a child with cystic fibrosis. If congenital absence of vas deferens is not caused by mutations in CFTR, the risk of having children with cystic fibrosis is not increased.

What other names do people use for congenital bilateral absence of vas deferens?

* Absence of vas deferens
* Absent vasa
* CAVD
* CBAVD
* Congenital absence of vas deferens
* Congenital aplasia of vas deferens