Association between genotype and pulmonary phenotype in cystic fibrosis patients with severe mutations

Background: Despite numerous studies a clear relationship between genotype and pulmonary phenotype has not been established within the group pancreatic insufficient cystic fibrosis (CF) patients. We studied the relationship between class I and class II mutations and pulmonary function in Swedish patients with known CFTR functional classification. Methods: 170 CF patients with two class II mutations, 18 with two class I mutations and 78 with a combination of class I and II mutations were included in the study. Spirometry was performed when patients were in an optimal clinical condition. Results: Patients with two class I mutations had lower lung function (FEV1 and FVC) compared to the group with either a combination of class I and II mutations or two class II mutations. Conclusion: CF patients carrying two class I mutations risk developing more severe lung disease compared to patients with at least one class II mutation. (C) 2011 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.