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CF Morbidity: Phenotypic expression of CF involves multiple organs

Cystic fibrosis (CF), a systemic, multiorgan disease, is caused by loss of CFTR protein-mediated ion transport (activity). Defective ion transport leads to an imbalance of fluid and electrolytes causing thick, sticky mucus and viscous secretions to accumulate in different organs. This interferes with the proper function of the lungs, pancreas, gastrointestinal system, sinuses, and reproductive system. In the sweat glands, loss of CFTR activity restricts reabsorption of chloride in the duct, limiting the amount of salt that can be reabsorbed.1-5

The morbidity of CF3-5*

What are the clinical effects of CFTR protein defects?

Click the circles on the body to review.
  • Nasal congestion
  • Loss of smell
  • Sinusitis
  • Chronic infection
  • Nasal polyps

Normal Physiology
  • Pancreatic insufficiency
  • Nutrient and fat malabsorption
  • Vitamin deficiency
  • Acute/chronic pancreatitis
  • CF-related diabetes mellitus

Normal Physiology
Gastrointestinal Tract
  • Nutrient malabsorption
  • Gastroesophageal reflux disease
  • Distal intestinal obstructive syndrome
  • Biliary duct obstruction
  • Focal biliary cirrhosis
  • Chronic constipation
Normal Physiology
Sweat Glands
  • Excessive salt loss
  • Dehydration
  • Chronic metabolic alkalosis
  • Heat prostration
  • High levels of sweat chloride

Normal Physiology
  • Cough, viscous sputum, dyspnea
  • Chronic endobronchial infections and inflammation
  • Bronchiectasis
  • End-stage lung disease
Normal Physiology
Reproductive System
  • Infertility
  • Congenital bilateral absence of vas deferens (CBAVD)

Normal Physiology

*CF can affect additional organs to the ones shown here (e.g., skeletal system).5

Symptoms of CF manifest throughout life with great variability among patients, though lung disease is the primary cause of mortality.1,5-7

Various factors influence an individual’s CF phenotype. Learn more.

  1. Zielenski J. Genotype and phenotype in cystic fibrosis. Respiration. 2000;67(2):117‐133.
  2. Orenstein DM, Spahr JE, Weiner DJ. Cystic Fibrosis: A Guide for Patient and Family. 4th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2012.
  3. Ramsey B, Richardson MA. Impact of sinusitis in cystic fibrosis. J Allergy Clin Immunol. 1992;90(3 Pt 2):547-552.
  4. O'Sullivan BP, Freedman SD. Cystic fibrosis. Lancet. 2009;373(9678):1891-1904.
  5. Welsh MJ, Ramsey BW, Accurso F, Cutting GR. Cystic fibrosis: membrane transport disorders. In: Valle D, Beaudet A, Vogelstein B, et al, eds. The Online Metabolic & Molecular Bases of Inherited Disease. The McGraw‐Hill Companies Inc; 2004:part 21, chap 201.
  6. European Cystic Fibrosis Society. ECFS Patient Registry 2010 Annual Data Report. 2014.
  7. Cystic Fibrosis Foundation. Cystic Fibrosis Foundation Patient Registry 2012 Annual Data Report. Bethesda, MD. © 2013 Cystic Fibrosis Foundation.