What is the disease pointed out by these features?
CYSTIC FIBROSIS. An autosomal recessive disorder caused by a single gene mutation, with a prevalence of 1/2000-4000 whites worldwide and much lowers in blacks. First identified in 1938, was termed CYSTIC FIBROSIS OF THE PANCREAS. The gene in question is the CFTR that encodes the cystic fibrosis transmembrane conductance regulator. Is a case of PLEIOTROPY since this mutation has multiple effects, among these problems in the regulation of Na+ ions transport among epithelial cells and a damaged regulation of chloride ion channels. Defective ion transport results in salt imbalances depleting the airway of water and producing a thick, obstructive secretions seen in the lungs. Cl- transport defect explains the abnormally high concentration of chloride ions in the sweat secretions of CF patients, because it cannot be reabsorbed from the lumen of the sweat duct. There are many classes of possible mutations in the CFTR gene, the most common is the F508del : a three-base deletion that results in loss of a phenylalanine residue in position 508 = complete lack of Cl- channel production. 85% of patients have pancreatic insufficiency, 10-25% of newborns with CF have meconium ileus, a bowel obstruction, 95% of males are sterile. Median survival time: 40y. Major causes of mortality: lower airway inflammation, chronic bronchial infection, fibrosis of the lung tissue, dehydrated airway surface , thick airway mucus, reduced clearance. FDA approved drug: IVACAFTOR. It increases CFTR channel activity in response to ATP and improve lung function of people affected with class 2 mutations.
