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The symptoms of CF usually develop during early childhood. Both lungs and pancreas produce abnormally viscous mucus. The mucus in the lungs can become a growth medium for bacteria, resulting in chronic respiratory infections and eventual permanent damage to the lung tissue. As lung function deteriorates, CF patients develop pulmonary hypertension and eventually cor pulmonale. Death usually occurs from severe infection or heart failure. These thick secretions also obstruct the pancreas, preventing digestive enzymes from reaching the intestines to help break down and absorb food.
The disease can be diagnosed by a high salt concentration in a baby's sweat or by genetic testing.
Cystic fibrosis(CF) was first described as a disease in the late 1930s. It is the most common genetic disease among people with European ancestry. Approximately one in every 25 people carries one normal and one CF gene. Since cystic fibrosis is recessive, both copies of the gene have to be CF genes to cause the symptoms that occur in about 1 in every 2500 children. The high incidence of this lethal gene can be explained by the fact that CF carriers, who don't show any symptoms, enjoy some protection against cholera, since the extreme water loss in the intestines is prevented. People from areas where cholera is not a problem show a much lower incidence of CF. Genetic counseling and genetic testing is recommended for families who may be carriers of cystic fibrosis.
In its most common form, a single amino acid mutation leads to the production of an abnormal transmembrane CFTR protein ( cystic fibrosis transmembrane conductance regulator ) which functions in transporting chloride ions across epithelial cells found in the lung and intestinal tract. Since water follows ions by osmosis, this results in water depletion and viscous mucus.
Recent medical research is beginning to show that an imbalance of essential fatty acids may play a role in cystic fibrosis. Tissue samples from both mice, and more recently humans, with CF show an excess of arachidonic acidArachidonic acid is a polyunsaturated fatty acid with four cis double bonds, which are the sources of its flexibility and give it the capacity to react with molecular oxygen. It is present in the membrane of the body's cells, and is a precursor in the pro (AA) and a deficiency of docosahexaenoic acid (DHA). Research has also indicated that healthy individuals with one copy of the CF gene and one copy of the normal gene have fatty acid levels in between those of CF patients and people with no CFTR gene mutations. Further research is needed to show how this is linked to the CFTR gene defect and what implications this may have on treatment of Cystic Fibrosis.
CF patients often cannot interact with each other socially due to worries of cross-infection of Pseudomonas, MRSA, Burkholderia cepacia , and other bacteria. These infections thrive in the thick mucus of CF patients' lungs and cause complications and possibly death. Therefore CF patients who do not have a certain bacteria type cannot meet with those who do. Because of this risk CF patients must remain in isolation during hospital stays, and special precautions must be taken. This risk previously caused many CF clinics to recommend that CF patients live in isolation and never meet. However recently these views have been changed because of the possible psychological problems this may cause; instead CF patients are encouraged to exercise caution, avoid direct physical contact, and possibly wear surgical masks.