High frequency of the R75Q CFTR variation in patients with chronic obstructive pulmonary disease.

We performed the complete screening of the CFTR gene in a group of 31 patients with COPD in order to investigate the impact of mutations and polymorphisms in the CFTR gene. The cumulative frequency of CFTR mutations (17.74%) was significantly higher than in our general population (P < 0.0001). The R75Q was significantly overrepresented in COPD patients (8.06%; P = 0.002). In all patients carrying the R75Q chronic bronchitis was a dominant symptom of COPD, and all were homozygous for the V470 allele. These findings suggest that R75Q mutation could be characteristic CFTR variant for COPD patients.