Molecular mechanisms of CFTR chloride channel dysfunction in cystic fibrosis.
In the last few years, there has been substantial progress in understanding cystic fibrosis (CF). CF was first described as a clinical syndrome in 1938, and an appreciation of its autosomal recessive nature followed shortly thereafter. The disease is usually manifested as exocrine pancreatic insufficiency, an increase in the sweat Cl- concentration, male infertility, and airway disease. Airway disease leads to progressive lung dysfunction, which is currently the major cause of morbidity and is responsible for 95% of CF mortality. Defective Cl- transport across affected epithelia is the hallmark of the disease although numerous other abnormalities have been described. The gene that encodes the cystic fibrosis transmembrane conductance regulator (CFTR) has been identified and over 200 CF-associated mutations within the gene have since been reported. CFTR is a regulated Cl- channel, for which structure-function relationships have begun to be established.