Cystic Fibrosis is caused by a mutation in the cystic fibrosis transmembrane conductance regulator gene (CFTR; 602421). The gene is located on the long (q) arm of chromosome 7 at position 31.2. There are 5 different mutations of this gene that can cause cystic fibrosis.
Frequency:
1 in 2500 newborn infants are born with cystic fibrosis. In 2013 just over 10,000 people were recorded to have cystic fibrosis in the UK. The most common mutation of the CFTR gene is Δf508. It is believed there are 70,000 cases of cystic fibrosis worldwide that are caused by this mutation, with 1000 new cases every year. The G542X mutation is most common in the Mediterranean with the highest frequency of 16.7% in the Balearic Islands …show more content…
If only one faulty CFTR gene is inherited the person is described as a carrier. Carriers show no symptoms of the disease and lead normal lives.
Gene …show more content…
For example the ΔF508 mutation is expressed more in the sweat glands than in the cells of the repiratory and intestinal epithelia (Kalin N et al, 1999). The tissue specificity of the CFTR mutation is dependent on the amount of CFTR mRNA transcribed in each of the epithelial cells. In the respiratory system and the intestinal tract of cystic fibrosis patients the expression of the CFTR mutation ranged from no expression of the protein to normal amounts which indicactes that the CFTR exprssion is higher in tissues with a higher cholride ion concentration (Kalin N et al, 1999).
Mechanistic Consequences:
The CFTR protein act as a channel that transports ions through the apical cell membrane of epithelial cells. These ions include chloride and bicorbonate ions, it also helps to regulate the balance of fluids in the epithelial tissues in the lungs, intestines, sweat glands and the pancreas (CFTR science, 2015). A mutation in the CFTR protein leads to a reduction or total loss of its ability to control ion transport in the cell. This leads to a fluid and electrolyte imbalance causing thick sticky mucus to accumulate. This mucus causes improper function in various organs.
Protein