Molecules involved in Cystic Fibrosis

Tough one to answer. All I know is that cystic fibrosis is caused by a defective chloride ion channel (cystic fibrosis transmembrane conductance regulator). There's a mutation in gene that codes for the protein which forms the channel. Chloride ions pass through it.

Mutations in the CFTR gene cause cystic fibrosis. The CFTR gene provides instructions for making a channel that transports negatively charged particles called chloride ions into and out of cells. Chloride is a component of sodium chloride, a common salt found in sweat. Chloride also has important functions in cells; for example, the flow of chloride ions helps control the movement of water in tissues, which is necessary for the production of thin, freely flowing mucus.

Mutations in the CFTR gene disrupt the function of the chloride channels, preventing them from regulating the flow of chloride ions and water across cell membranes. As a result, cells that line the passageways of the lungs, pancreas, and other organs produce mucus that is unusually thick and sticky. This mucus clogs the airways and various ducts, causing the characteristic signs and symptoms of cystic fibrosis.

Other genetic and environmental factors likely influence the severity of the condition. For example, mutations in genes other than CFTR might help explain why some people with cystic fibrosis are more severely affected than others. Most of these genetic changes have not been identified, however.