Question

11. Cystic Fibrosis is a terrible disease. What causes cystic fibrosis? Be specific as possible. (Hint:

You need the internet for this one and by “be specific” I mean you need to find a specific mutation in

the protein’s primary sequence. There is more than one but you only need to find one).

Answer 1

Cystic fibrosis is a genetic disease. People with CF have inherited two copies of the defective CF gene -- one copy from each parent. Both parents must have at least one copy of the defective gene. People with only one copy of the defective CF gene are called carriers, but they do not have the disease.

A defect in the CFTR gene causes cystic fibrosis (CF). This gene makes a protein that controls the movement of salt and water in and out of your body's cells. In people who have CF, the gene makes a protein that doesn't work well. This causes thick, sticky mucus and very salty sweat.

Specifically F508del-CFTR, or delta-F508 (ΔF508), is the most common CFTR mutation leading to cystic fibrosis. F508del-CFTR is a class II mutation. A deletion of three nucleotides in the gene leads to the deletion of the phenylalanine residue at position 508 of the polypeptide chain.