Cystic Fibrosis CF is a genetically caused disease a What

Cystic Fibrosis ( CF ) is a genetically caused disease;

a) What do you know about this disease and its causes?

b) Why some mutations in the CF gene might cause CF symptoms while other mutations might not?

c) In which part of the CF gene is the mutation that is detected by the new genetic test located?

d) How is this new mutation affecting the CF gene?

e) What tissue can parents provide easily for the genetic analysis?

f) Explain the concept of same DNA in all body tissues.

Solution

A. Cystic fibrosis is an autosomal recessive genetic disorder caused due to a mutation in a gene called CFTR ( cystic fibrosis transmembrane conductance regulator). This disorder is characterized by the buildup of thick, sticky mucus inside air ways and affects mostly lungs but sometimes pancreas and kidney also.

The CFTR gene is located on q31.2 locus of chromosome 7. This gene provides instructions for making a channel called chloride channel that transports chloride ions into and out of cells. Chloride is a component of sodium chloride, a common salt found in sweat. 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.