Establishing a diagnosis of cystic fibrosis

Cystic fibrosis (CF) is a recessively inherited condition caused by mutation of the cystic fibrosis transmembrane conductance regulator (CFTR) gene. Characterization of the genetic defect has improved understanding of the condition and, in the majority of cases, diagnosis is straightforward. However, in a significant number, diagnosis remains a challenge. This paper will discuss the management of these issues and reflect on atypical presentations. In addition we will discuss situations in which genetic variations of the CFTR gene are not associated with a classical CF phenotype and the implications for practice in both paediatric and adult clinics.