PGx cystic fibrosis

CFTR encodes the cystic fibrosis transmembrane conductance regulator, a chloride channel that plays an essential role in epithelial salt and fluid transport. Variants that impair CFTR function cause and influence response to CFTR-modulator therapies. Because different modulators target specific functional defects of the CFTR protein, treatment eligibility depends on the underlying CFTR genotype. While many disease-causing variants are associated with response to currently approved modulators, variants that result in absent CFTR protein production may limit therapeutic options.

Genetic testing is therefore required to determine eligibility for genotype-directed treatment.

The report describes the identified CFTR genotype and its relevance for currently approved CFTR-modulator therapies. The interpretation considers the combination of CFTR variants present and their expected impact on CFTR function.

While comprehensive CFTR analysis provides a robust assessment of therapeutically relevant variants, a negative result does not completely exclude all clinically relevant genetic changes. Eligibility for CFTR-modulator therapy also depends on clinical and regulatory criteria beyond genotype.

Confirmation of the CFTR genotype is required to assess eligibility for CFTR-modulator therapy. The identified genotype is interpreted in the context of current therapeutic indications and regulatory guidance. Results should always be considered together with the patient’s clinical presentation and treatment decisions remain the responsibility of the treating physician.

• Clancy JP, Johnson SG, Yee SW, McDonagh EM, Caudle KE, Klein TE, et al. Clinical Pharmacogenetics Implementation Consortium (CPIC) guideline for ivacaftor therapy in the context of CFTR genotype. Clin Pharmacol Ther. 2014;95(6):592-597. PMID: .
• European Medicines Agency. Symkevi (tezacaftor/ivacaftor): EPAR, product information. Product information last updated December 8, 2025. Available from:
• European Medicines Agency. Kaftrio (ivacaftor/tezacaftor/elexacaftor): EPAR, product information. Product information last updated March 19, 2026. Available from:
• European Medicines Agency. Alyftrek (deutivacaftor/tezacaftor/vanzacaftor): EPAR, product information. Product information last updated March 30, 2026. Available from:
• Southern KW, Castellani C, Lammertyn E, Smyth A, VanDevanter D, van Koningsbruggen-Rietschel S, et al. Standards of care for CFTR variant-specific therapy (including modulators) for people with cystic fibrosis. J Cyst Fibros. 2023;22(1):17-30. PMID: .