Glossary of Terms

Glossary of terms


Cardiovascular exercise: Exercise that raises your heart rate.

CFTR gene mutations: We know of over 2,000 different CFTR gene mutations. At least 281 of which cause CF.1 If both of the CFTR genes you inherit have a mutation that causes CF, you are born with CF. People with CF can either have two copies of the same CFTR mutation, or two different CFTR mutations.2

CFQ-R: The Cystic Fibrosis Questionnaire – Revised (CFQ-R) is used to measure the impact of a treatment on a person’s overall health, daily life, well-being and symptoms.3

Chloride ion: Chloride plays an important role in the body. The movement of chloride ions into and out of cells helps control the movement of water in the body. This is needed to keep the mucus protecting our airways and digestive tract thin and watery so organs such as the lungs, pancreas, liver and intestines can all function normally. Chloride also makes up part of salts such as sodium chloride which is found in sweat.4

Cystic Fibrosis Transmembrane conductance Regulator (CFTR) gene: The CFTR gene tells the body to produce CFTR proteins, channels which control the movement of salt and water into and out of cells in a number of organs, including the lungs.5

Enzymes: Substances produced by the pancreas which help break food into very small fragments which can be absorbed into the blood-stream.6

FEV1: Forced expiratory volume in one second (FEV1) measures the amount of air a person can exhale in one second.It is used to measure how well a person’s lungs are functioning.

Genes: Genes are like an instruction manual for the body and carry the code that determines our physical characteristics (height, eye and hair colour, etc.) and much more. People have two copies of most genes, one copy from their father and one from their mother.7

Gene mutations: Sometimes changes or mistakes occur in genes, these are called mutations. Some mutations may cause the gene to behave differently from normal. This can result in a person having certain diseases like CF.7

Genotype: The combination of genes you inherited from your parents.

Lung disease: Reduced lung function due to repeated infections and inflammation.8

Pancreas: Part of the digestive system found just behind your stomach. It produces enzymes that help break down food, and insulin, which helps to keep the amount of glucose in the blood stable.6

Pulmonary exacerbations: Periods of worsening respiratory symptoms that require antibiotic treatment and/or hospital admission.3


  1. The Clinical and Functional Translation of CFTR (CFTR2) website.

  2. 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. Available at:

  3. Ramsey BW, Davies J, McElvaney NG et al. A CFTR potentiator in patients with cystic fibrosis and the G551D mutation. New England Journal of Medicine. 2011;365(18):1663-72.

  4. U.S. National Library of Medicine website.

  5. Zielenski J. Genotype and phenotype in cystic fibrosis. Respiration. 2000;67(2):117‐133.

  6. Cancer Research UK website.

  7. NHS Choices website.

  8. O'Sullivan B, Freedman S. Cystic fibrosis. Lancet. 2009; 373(9678): 1891–1904.