Analysis of exocrine pancreatic function in cystic fibrosis: one mild CFTRmutation does not exclude pancreatic insufficiency

Background Cystic fibrosis (CF) is the most common cause of exocrine pancre atic insufficiency in childhood. The aim of the present study is to evaluat e the correlation between genotype and exocrine pancreatic insufficiency in CF patients. The special emphasis was put on-the analysis of mild CFTR mut ations. Design The study comprised 394 CF patients and 105 healthy subjects (HS). E lastase-1 concentrations were measured in all subjects. Results Severe pancreatic insufficiency was associated with the presence of two CFTR gene mutations (AF508, N1303K, CFTR dele 2,3 (21kb), G542X, 1717- 1G-A, R533X, W1282X, 621GT, 2183AAG, R560T, 2184insA and Delta I507, G551D 895T) and mild insufficiency with the presence of at least one mutation (R1 17H, 3171insC, A155P2; 138insL, 296 + 1G-A, E92GK, E217TG, 2789 + 5G-A. 384 9 + 1kbC-T/3849 + 1kbC-T) genotype resulted in high elastase-1-values. Howe ver in case of patients with genotype Delta F508/3849 + 10kbC-T, 1717-1GA/3 849 + 10kbC-T as well as with Delta F508/R334W, both high and low elastase- 1 concentrations were found. Low E1 values were found in a patient with Del ta F508/R347P genotype. Conclusion Patients who carry two 'severe' mutations develop pancreatic ins ufficiency, whereas those who carry at least one 'mild' usually remain panc reatic sufficient. However, the presence of one mild mutation does not excl ude pancreatic insufficiency.