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Cystic fibrosis

Reviewed January 2008

What is cystic fibrosis?

Cystic fibrosis is an inherited disease of the mucus glands that affects many body systems. The disorder's most common signs and symptoms include progressive damage to the respiratory system and chronic digestive system problems.

Mucus is a slippery substance that lubricates and protects the linings of the airways, digestive system, reproductive system, and other organs and tissues. In people with cystic fibrosis, the body produces mucus that is abnormally thick and sticky. This abnormal mucus can obstruct the airways, leading to severe problems with breathing and bacterial infections in the lungs. These infections cause chronic coughing, wheezing, and inflammation. Over time, mucus buildup and infections result in permanent lung damage, including the formation of scar tissue (fibrosis) and cysts in the lungs.

Most people with cystic fibrosis also have digestive problems because thick, sticky mucus interferes with the function of the pancreas. The pancreas is an organ that produces insulin (a hormone that helps control blood sugar levels). It also makes enzymes that help digest food. In people with cystic fibrosis, mucus blocks the ducts of the pancreas, preventing these enzymes from reaching the intestines to aid digestion. Problems with digestion can lead to diarrhea, malnutrition, poor growth, and weight loss. Some babies with cystic fibrosis have meconium ileus, a blockage of the intestine that occurs shortly after birth.

Cystic fibrosis used to be considered a fatal disease of childhood. With improved treatments and better ways to manage the disease, many people with cystic fibrosis now live well into adulthood. Adults with cystic fibrosis experience medical problems affecting the respiratory, digestive, and reproductive systems. For example, most men with cystic fibrosis are unable to father children (infertile) because the tubes that carry sperm (the vas deferens) are blocked by mucus and do not develop properly. This condition is known as congenital bilateral absence of the vas deferens (CBAVD). Infertility is also possible, though less common, in women with cystic fibrosis.

How common is cystic fibrosis?

Cystic fibrosis is a common genetic disease within the Caucasian (white) population in the United States. The disease occurs in 1 in 2,500 to 3,500 Caucasian newborns. Cystic fibrosis is less common in other ethnic groups, affecting about 1 in 17,000 African Americans and 1 in 31,000 Asian Americans.

What genes are related to cystic fibrosis?

Mutations in the CFTR gene cause cystic fibrosis.

The CFTR gene provides instructions for making a channel that transports negatively charged particles called chloride ions into and out of cells. The flow of chloride ions helps control the movement of water in tissues, which is necessary for the production of thin, freely flowing mucus.

Mutations in the CFTR gene disrupt the function of the chloride channels, preventing them from regulating the flow of chloride ions and water across cell membranes. As a result, cells that line the passageways of the lungs, pancreas, and other organs produce mucus that is unusually thick and sticky. This mucus clogs the airways and glands, causing the characteristic signs and symptoms of cystic fibrosis.

Other genetic and environmental factors likely influence the severity of the condition. For example, mutations in genes other than CFTR might help explain why some people with cystic fibrosis are more severely affected than others. Most of these genetic changes have not been identified, however.

How do people inherit cystic fibrosis?

This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.

Where can I find information about treatment for cystic fibrosis?

You may find information on treatment or management of cystic fibrosis or some of its symptoms in the links below, particularly the links for Gene Reviews, MedlinePlus Encyclopedia, Educational resources, and Patient support.

Where can I find additional information about cystic fibrosis?

You may find the following resources about cystic fibrosis helpful. These materials are written for the general public.

  • MedlinePlus - Health information
    • Encyclopedia: Cystic Fibrosis (http://www.nlm.nih.gov/medlineplus/ency/article/000107.htm)
    • Encyclopedia: Cystic fibrosis - nutritional considerations (http://www.nlm.nih.gov/medlineplus/ency/article/002437.htm)
    • Encyclopedia: Cystic fibrosis - resources (http://www.nlm.nih.gov/medlineplus/ency/article/002176.htm)
    • Health Topic: Cystic Fibrosis (http://www.nlm.nih.gov/medlineplus/cysticfibrosis.html)
    • Health Topic: Newborn Screening (http://www.nlm.nih.gov/medlineplus/newbornscreening.html)
    • Tutorials: Cystic Fibrosis (http://www.nlm.nih.gov/medlineplus/tutorials/cysticfibrosis/htm/index.htm)
  • Additional NIH Resources - National Institutes of Health
    • National Center for Biotechnology Information: Genes and Disease (http://www.ncbi.nlm.nih.gov/books/bv.fcgi?call=bv.View..ShowSection&rid=gnd.section.168)
    • National Heart, Lung, and Blood Institute (http://www.nhlbi.nih.gov/health/dci/Diseases/cf/cf_what.html)
    • National Human Genome Research Institute (http://www.genome.gov/10001213)
  • Educational resources - Information pages
    • American College of Obstetricians and Gynecologists (http://www.acog.com/from_home/wellness/cf002.htm)
    • Ask the Geneticist: Inheritance of cystic fibrosis (http://www.genetics.emory.edu/ask/question.php?question_id=606)
    • Ask the Geneticist: Life expectancy of people with cystic fibrosis (http://www.genetics.emory.edu/ask/question.php?question_id=1660)
    • Centre for Genetics Education (http://www.genetics.com.au/pdf/factsheets/fs33.pdf)
    • Children's Hospital Boston (http://www.childrenshospital.org/az/Site1711/mainpageS1711P0.html)
    • Emory University School of Medicine: Cystic fibrosis carrier testing (http://www.genetics.emory.edu/pdf/Emory_Human_Genetics_Cystic_Fibrosis_Carrier.PDF)
    • Genetic Science Learning Center, University of Utah (http://learn.genetics.utah.edu/content/disorders/whataregd/cf/index.html)
    • KidsHealth from the Nemours Foundation (http://kidshealth.org/kid/health_problems/heart/cystic_fibrosis.html)
    • Lab Tests Online (http://labtestsonline.org/understanding/conditions/cystic_fibrosis.html)
    • Madisons Foundation (http://www.madisonsfoundation.org/index.php/component/option,com_mpower/diseaseID,73/)
    • Merck Manual of Medical Information, Second Home Edition (http://www.merck.com/mmhe/sec04/ch053/ch053a.html)
    • NetWellness (http://www.netwellness.org/healthtopics/cysticfibrosis/overview.cfm)
    • New York Online Access to Health (NOAH) (http://www.noah-health.org/en/lung/conditions/cystic/)
    • Office of Science, U.S. Department of Energy (http://www.ornl.gov/sci/techresources/Human_Genome/posters/chromosome/cf.shtml)
    • Orphanet (http://www.orpha.net/consor/cgi-bin/OC_Exp.php?Lng=EN&Expert=586)
    • Pacific Northwest Regional Genetics Group (PacNoRGG) (http://mchneighborhood.ichp.edu/pacnorgg/media/CysticFibrosis/BothCarriers.pdf)
    • Save Babies Through Screening Foundation, Inc. (http://www.savebabies.org/diseasedescriptions/cysticfibrosis.php)
    • The Cleveland Clinic Health Information Center (http://www.clevelandclinic.org/health/health-info/docs/2300/2372.asp?index=9358)
    • The Wellcome Trust (http://genome.wellcome.ac.uk/doc_WTD020856.html)
    • Virginia Department of Health (http://www.vahealth.org/genetics/documents/ParentfactsPDF/Cystic%20Fibrosis%20-%20Parent%20Fact%20Sheet.pdf)
  • Patient support - For patients and families
    • American Lung Association (http://www.lungusa.org/site/pp.asp?c=dvLUK9O0E&b=35042)
    • Canadian Cystic Fibrosis Foundation (http://www.cysticfibrosis.ca/)
    • Cystic Fibrosis Foundation (http://www.cff.org)
    • Cystic Fibrosis Trust (UK) (http://www.cftrust.org.uk/)
    • Family Village (http://www.familyvillage.wisc.edu/lib_cysf.htm)
    • March of Dimes (http://www.marchofdimes.com/pnhec/4439_1213.asp)
    • National Organization for Rare Disorders (http://www.rarediseases.org/search/rdbdetail_abstract.html?disname=Cystic+Fibrosis)
    • Resource list from the University of Kansas Medical Center (http://www.kumc.edu/gec/support/cystic_f.html)

You may also be interested in these resources, which are designed for healthcare professionals and researchers.

  • Gene Reviews - Clinical summary (http://www.ncbi.nlm.nih.gov/bookshelf/br.fcgi?book=gene&part=cf)
  • Gene Tests - DNA tests ordered by healthcare professionals (http://www.genetests.org/query?testid=2220)
  • Genetic Tools - Teaching cases (http://www.genetests.org/servlet/access?fcn=y&filename=/tools/cases/cf-12/)
  • ACTion Sheets - Newborn screening follow up
    • ACTion sheet: Elevated IRT +/- DNA (http://www.acmg.net/resources/policies/ACT/Act_Sheet-CF_4-17-06.pdf)
  • ClinicalTrials.gov - Linking patients to medical research (http://clinicaltrials.gov/search/condition=%22cystic+fibrosis%22)
  • PubMed - Recent literature (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?CMD=search&DB=PubMed&term=(Cystic+Fibrosis[MAJR])+AND+(cystic+fibrosis[TI])+AND+genetics[mh]+AND+review[pt]+AND+english[la]+AND+human[mh]&orig_db=PubMed&filters=ON&pmfilter_EDatLimit=1800+Days)
  • Online Books - Medical and science texts
    Scriver's Online Metabolic and Molecular Bases of Inherited Disease (OMMBID): Cystic Fibrosis (http://books.mcgraw-hill.com/getommbid.php?isbn=0071459960&template=ommbid&c=201)
  • OMIM - Genetic disorder catalog (http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=219700)

What other names do people use for cystic fibrosis?

  • CF
  • Cystic fibrosis of pancreas
  • Fibrocystic Disease of Pancreas
  • Mucoviscidosis

See How are genetic conditions and genes named? (http://ghr.nlm.nih.gov/handbook/mutationsanddisorders/naming) in the Handbook.

What if I still have specific questions about cystic fibrosis?

  • See How can I find a genetics professional in my area? (http://ghr.nlm.nih.gov/handbook/consult/findingprofessional) in the Handbook.
  • Ask the Genetic and Rare Diseases Information Center (http://rarediseases.info.nih.gov/GARD/).
  • Submit your question to Ask the Geneticist (http://www.askthegen.org/).

What glossary definitions help with understanding cystic fibrosis?

autosomal ; autosomal recessive ; cell ; cell membrane ; channel ; charged particles ; chloride ; chloride channels ; chloride ion ; chronic ; congenital ; cysts ; digestion ; digestive ; digestive system ; duct ; enzyme ; fibrosis ; gene ; hormone ; infection ; infertile ; infertility ; inflammation ; insulin ; intestine ; ions ; meconium ; mucus ; mutation ; newborn screening ; pancreas ; pancreatic ; population ; recessive ; respiratory ; screening ; sign ; sperm ; symptom ; tissue ; vas deferens ; wheezing

You may find definitions for these and many other terms in the Genetics Home Reference Glossary (http://www.ghr.nlm.nih.gov/glossary).

References
  • Accurso FJ. Update in cystic fibrosis 2005. Am J Respir Crit Care Med. 2006 May 1;173(9):944-7. Review. No abstract available. (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=retrieve&db=pubmed&dopt=Abstract&list_uids=16632633)
  • Gardner J. What you need to know about cystic fibrosis. Nursing. 2007 Jul;37(7):52-5. Review. (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=retrieve&db=pubmed&dopt=Abstract&list_uids=17603376)
  • Gene Review (http://www.ncbi.nlm.nih.gov/bookshelf/br.fcgi?book=gene&part=cf)
  • Gershman AJ, Mehta AC, Infeld M, Budev MM. Cystic fibrosis in adults: an overview for the internist. Cleve Clin J Med. 2006 Dec;73(12):1065-74. Review. (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=retrieve&db=pubmed&dopt=Abstract&list_uids=17190310)
  • Merlo CA, Boyle MP. Modifier genes in cystic fibrosis lung disease. J Lab Clin Med. 2003 Apr;141(4):237-41. Review. (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=retrieve&db=pubmed&dopt=Abstract&list_uids=12677168)
  • Ratjen F, Doring G. Cystic fibrosis. Lancet. 2003 Feb 22;361(9358):681-9. Review. (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=retrieve&db=pubmed&dopt=Abstract&list_uids=12606185)
  • Rowe SM, Miller S, Sorscher EJ. Cystic fibrosis. N Engl J Med. 2005 May 12;352(19):1992-2001. No abstract available. (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=retrieve&db=pubmed&dopt=Abstract&list_uids=15888700)

 

The resources on this site should not be used as a substitute for professional medical care or advice. Users seeking information about a personal genetic disease, syndrome, or condition should consult with a qualified healthcare professional. See How can I find a genetics professional in my area? (http://ghr.nlm.nih.gov/handbook/consult/findingprofessional) in the Handbook.

 
Reviewed: January 2008
Published: January 23, 2009