Cystic Fibrosis

Cystic fibrosis History Symptomatic diseases Diagnosis and monitoring Treatment Prognosis

Cystic fibrosis

Cystic fibrosis (also known as CF, mucovoidosis, or mucoviscidosis) is a hereditary disease affecting the exocrine (mucus) glands of the lungs, liver, pancreas, and intestines, causing progressive disability due to multisystem failure.

Thick mucus production results in frequent lung infections. Diminished secretion of pancreatic enzymes is the main cause of poor growth, greasy stools, and deficiency in fat-soluble vitamins. Males can be infertile due to the condition congenital bilateral absence of the vas deferens. Often, symptoms of CF appear in infancy and childhood. Meconium ileus is a typical finding in newborn babies with CF.

Individuals with cystic fibrosis can be diagnosed prior to birth by genetic testing. Newborn screening tests are increasingly common and effective (although false positives may occur, and children need to be brought in for a sweat test to distinguish disease vs carrier status). The diagnosis of CF may be confirmed if high levels of salt are found during a sweat test, although some false positives may occur.

There is no cure for CF, and most individuals with cystic fibrosis die young: many in their 20s and 30s from lung failure. The predicted median age of survival for a person with CF is 37 years. However, with the continuous introduction of many new treatments, the life expectancy of a person with CF is increasing to ages as high as 40 or 50. Lung transplantation is often necessary as CF worsens.

Cystic fibrosis is one of the most common life-shortening, genetic diseases. In the United States, 1 in 4,000 children are born with CF. It is most common among western European populations; one in twenty-two people of Mediterranean descent are carriers of one gene for CF, making it the most common genetic disease in these populations.

CF is caused by a mutation in the gene, cystic fibrosis transmembrane conductance regulator (CFTR). The product of this gene is a chloride ion channel important in creating sweat, digestive juices, and mucus. Although most people without CF have two working copies (alleles) of the CFTR gene, only one is needed to prevent cystic fibrosis. CF develops when neither allele can produce a functional CFTR protein. Therefore, CF is considered an autosomal recessive disease.