Cystic Fibrosis (Mucoviscidosis, CF) [E84.9]
Dr. rer. biol. hum. Soheyla Chahrokh-Zadeh
Cystic fibrosis (CF) is the most common autosomal recessiv genetic disorder in Caucasians (incidence approx. 1 in 2,500, heterozygote frequency approx. 1 in 25). Mutations in CFTR (Cystic Fibrosis Transmembrane Conductance Regulator) gene lead to dysfunction of chloride channels in the apical membrane of glandular epithelium and thus to a change of salt contents of sweat and other body secretions. This causes the production of the characteristic abnormally viscous mucus. The disease mostly affects the bronchial system, is progressive and associated with frequent infections. The gastrointestinal tract can be affected due to the impaired secretory function of the pancreas. In approx. 85% of all patients a pancreatic insufficiency occurs. The average life expectancy of affected individuals is about 30–40 years of age. Every 25th individual in the western industrialized countries is an asymptomatic carrier of a CFTR mutation. Offspring from two carriers have a 25% chance of developing CF. In many populations F50del is the most frequently detected mutation. Depending on the type and severity of the CFTR mutations the manifestation of the disease can be different. Besides classical CF there are atypical forms (CFTR-RD (related disease)) such as disseminated bronchiectasis, atypical chronic rhinosinusitis, chronic pancreatitis (see chapter pancreatitis) and CBAVD (congenital bilateral aplasia of the vas deferens, see chapter reproductive genetics).