A complete screening of the CFTR gene by DGGE and DNA sequencing was performed in patients with sarcoidosis. In 8/26 cases, missense and splicing CFTR gene mutations were found, a significant difference over controls (9/89) from the same population (P = 0.014). The odds ratio for a person with a CFTR gene mutation to develop the disease is 3.95 (1.18 < OR < 13.26). Seven different CFTR gene mutations were observed: R75Q, R347P, 621 + 3 A/G, 1898 + 3 A/G, L997F, G1069R, and a novel mutation which was detected in this study, I991V. R75Q mutation was present in 3/26 patients, a significant increase (P = 0. 01) in cases over controls, indicating its preferential association with sarcoidosis. A trend towards disease progression was observed in patients with CFTR gene mutations compared to patients without mutations. These data suggest that CFTR gene mutations predispose to the development of sarcoidosis.