The prevalence of CFTR mutations in patients with chronic rhinosinusitis: A systematic review and meta-analysis

Objectives: Undetected cystic fibrosis transmembrane regulator (CFTR) mutations may predispose individuals to develop CRS independent of formal CF diagnosis. The objective of this study was to determine the prevalence of CFTR mutations among individuals with CRS. Design: A systematic search following PRISMA guidelines was performed. A meta-analysis was performed to calculate pooled estimates for the prevalence of any CFTR mutation and for the DF508 mutation. Setting and participants: The systematic search included all studies identifying adults diagnosed with CRS, with no limitation to region or publication date. Studies had to identify a sample of patients previously diagnosed with CRS but not with CF and reporting testing for the prevalence of CF or the CFTR gene mutation. Main outcome measures: Prevalence of CFTR mutations among the general CRS population, with subgroup analysis of individuals with the dF508 mutation. Results and conclusions: The 6 included studies represented five countries: the United States, the UK, France, Poland and Finland. The pooled prevalence of CFTR mutations of any kind in CRS subjects without CF was 5.65% (RE 95% CI 2.99 - 10.41). The overall prevalence for the dF508 mutation was 4.22% (RE 95% CI 1.71 - 10.07). These estimates were significantly higher than the baseline estimated prevalence of CFTR carrier status of 3%-4% in the general population. However, the clinical relevance of the presence of CFTR mutations in CRS patients who have not been diagnosed with CF is currently unclear. Future studies should include sweat chloride testing as a measure of CFTR function.