The spectrum of CFTR-related disease.

There is increasing appreciation for the presence of diseases which do not fit the criteria for classic cystic fibrosis but are caused by dysfunction of the cystic fibrosis transmembrane conductance regulator (CFTR). This case describes a patient with documented CFTR dysfunction by nasal potential difference measurement who presents with chronic idiopathic pancreatitis, sinusitis, and allergic bronchopulmonary aspergillosis (ABPA), but not congenital bilateral absence of the vas deferens (CBAVD) or other classic symptoms of cystic fibrosis. This rare case demonstrates both the spectrum of disease which can be seen with CFTR dysfunction and the steps required to document CFTR involvement.