Not everyone with cystic fibrosis (CF) has the same mutations (changes) in their CFTR* genes. We know of over 2,000 different CFTR gene mutations. At least 242 of these cause CF but most are extremely rare.1
The five most common CFTR gene mutations are F508del, G542X, G551D, N1303K and W1282X.1
F508del is the most common CFTR gene mutation, it is estimated that over two thirds of all CFTR gene mutations worldwide are F508del.2 The next most common mutations, G542X, G551D, N1303K and W1282X, each have a worldwide prevalence of just 1-3%.3
Knowing your CF genotype
People with CF can either have two copies of the same CF mutation, or two different CF mutations.4
Your doctor should be able to tell you which CFTR gene mutations you have, this is called your ‘genotype’. If your CFTR mutations aren’t noted in your medical records it’s important to find out which mutations you have. This can be done using a genetic test provided by your doctor.4
*CFTR = Cystic fibrosis transmembrane conductance regulator
1. US CF Foundation, Johns Hopkins University, The Hospital for Sick Children. The Clinical and Functional Translation of CFTR (CFTR2). Available from: http://www.cftr2.org/mutations_history.php. Accessed June 2016.
2. Bobadilla JL, et al. Cystic Fibrosis: A Worldwide Analysis of Mutations Correlation With Incidence Data and Application to Screening. Human Mutation. 2002; 19: 575 ̶ 606.
3. Derichs N, et al. Targeting a genetic defect: cystic fibrosis transmembrane conductance regulator modulators in cystic fibrosis. European Respiratory Review 2013; 22(127): 58 ̶ 65.
4. 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. www.ommbid.com.