In: Biology
What is cystic fibrosis? Describe the major genetic cause and
the mechanism that leads to the
symptoms of the disease.
Cystic fibrosis (CF) is an inherited disease that affects mostly the lungs, but also the pancreas, liver, kidneys, and intestine. CF is inherited in an autosomal recessive manner which means it is caused by the presence of mutations in both copies of the gene. Those with a single mutated copy are carriers and are mostly healthy.
Genetic cause
The gene that is mutated in CF is the Cystic fibrosis transmembrane conductance regulator (CFTR) gene that encodes the Cystic fibrosis transmembrane conductance regulator (CFTR) protein.
Mechanism
CFTR protein is important in the production of sweat, digestive fluids, and mucus. The CFTR protein is located in every organ of the body that makes mucus. Mutations in the CFTR gene disrupt the function of the chloride channels, which affect the cells that line the passageways of the lungs, pancreas, and other organs. In individuals with mutated CFTR gene, these secretions by these cells, which are usually thin, will become thick. The condition can be diagnosed by a sweat test and genetic testing. There is no known cure for cystic fibrosis.
The thick, sticky mucus causes blockages in the lungs and digestive system. In normal individuals, mucus coats cilia in the airways of the respiratory organs. The mucus particles are swept up to the nose and mouth where the body can get rid of them. But, in people who have cystic fibrosis, this process does not work properly and leads to clogging of airways. Some patients have few or no symptoms, while others experience severe symptoms or life-threatening complications. Sticky mucus can lead to blockages, damage, or infections in the affected organs in them. Inflammation may develop too that can lead to damages to organs such as the lungs and pancreas.