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 (CF) is a genetically-inherited disease which is autosomal recessive in nature that primarily affects the lungs. Other organs that get affected are liver, kidney, pancreas and intestine. Lung infections due to mucus-clogged airways result in breathing problems. In case of pancreas, the secreted mucus does not allow the release of the important digestive enzymes needed by the body to breakdown food and absorb vital nutrients. Clubbing of fingers and toes, affected growth, infection in sinus include the other symptoms. Till now, no cure has been developed for this disease.

Cystic Fibrosis is caused by a defect in Cystic fibrosis transmembrane conductance regulator (CFTR) gene whose function is to control the entry and exit of chloride ions into and from our body\'s cells. Thus a defective CFTR cannot produce a proper protein causing CF.

b) Thousands of mutations are possible that affect the CFTR gene in many ways possible. The most common mutation of CFTR is a deletion mutation at position 508 of the sequence where 3 DNA nucleotides are deleted causing leading to deletion of phenylalanine. Other mutations also affect the CFTR gene which may or may not have symptoms of CF, but have some oter mild effects. Such diseases may be called \"CF-related diseases\".

c) Mutations at the 508th position (DF508) in the CFTR gene located on human chromosome 7 cause CF symptoms.

e) Pre-natal diagnosis include Chorionic villus sampling that tests the placental tissue and amniocentesis.