Mild cystic fibrosis in patients with the rare P5L CFTR mutation.

Over 1800 Cystic Fibrosis Transmembrane Conductance Regulator gene (CFTR) mutations have been identified so far, determining different degrees of CFTR dysfunction and a range of different cystic fibrosis phenotypes. The P5L CFTR mutation is a recently described N-terminus missense variant which may cause defect of protein folding and processing/trafficking, but the functional classification is still unclear. Given the rarity of the mutation, the associated clinical phenotype is still unknown.