CFTR

The CFTR gene provides instructions for making a protein called the cystic fibrosis transmembrane conductance regulator. This protein functions as a channel across the cell membrane. Such channels are found in tissues that produce mucus, sweat, saliva, tears, and digestive enzymes. Chloride, a component of salt, is transported through the channels in response to cellular signals. The transport of chloride helps control the movement of water in tissues and maintain the fluid consistency of these secretions. Proper functioning of these channels ensures that organs such as the lungs and kidneys function properly.

congenital bilateral absence of vas deferens - caused by mutations in the CFTR gene

Men with congenital bilateral absence of vas deferens most often have a mild mutation (a change that allows partial function of the gene) in one copy of the CFTR gene and a cystic fibrosis-causing mutation in the other copy of CFTR. As a result of these mutations, the movement of water and salt into and out of cells is disrupted. This disturbance leads to the production of a large amount of thick mucus that blocks the developing vas deferens (tubes that carry sperm from the testes).

cystic fibrosis - caused by mutations in the CFTR gene

More than 900 mutations in the CFTR gene have been found to cause cystic fibrosis. Most of these mutations either substitute one DNA base (the building material of DNA) for another or delete of a small number of DNA bases. The most common mutation, called delta F508, is a deletion of three base pairs at position 508 in the CFTR gene. All of the disease-causing mutations in the CFTR gene lead to a blockage of the movement of salt and water into and out of cells. As a result of this blockage, cells that line the passageways of the lungs, pancreas, and other organs produce the abnormally thick mucus characteristic of cystic fibrosis.

7q31.2

The CFTR gene is located on the long (q) arm of chromosome 7 at position 31.2.

See How do geneticists indicate the location of a gene? in the Handbook.

You and your healthcare professional may find the following resources about CFTR helpful.

• ClinicalTrials.gov - Linking patients to medical research
• Gene Reviews - Clinical summary
• Gene Tests - DNA tests ordered by healthcare professionals

You may also be interested in these resources, which are designed for genetics professionals and researchers.

• PubMed - Recent literature
• OMIM - Genetic disorder catalog
• Research Resources - Tools for researchers (4 links)

See How are genetic conditions and genes named? in the Handbook.

The Handbook provides basic information about genetics in clear language.

• What is DNA?
• What is a gene?
• How does a gene make a protein?
• How can gene mutations cause disorders?

These links provide additional genetics resources that may be useful.

• Genetics education
• Human Genome Project
• Resources for Genetic Researchers

ATP ; base pair ; cell membrane ; channel ; chloride ; congenital ; deletion ; digestive ; disease-causing mutation ; DNA ; DNA base ; enzyme ; gene ; mutation ; protein ; secretion ; testes ; transmembrane ; vas deferens

You may find definitions for these and many other terms in the Genetics Home Reference Glossary.