Clinical Phenotype and Genotype of Children with Borderline Sweat Test and Abnormal Nasal Epithelial Chloride Transport
Abstract
A significant number of children have symptoms suggestive of cystic fibrosis (CF) but cannot be definitively diagnosed because they have a sweat chloride level in the intermediate range, between 30 and 60 mmol/L, and only one or no identified CF-causing mutation. Our collaborative international study in children in this equivocal situation found that those with nasal potential difference results in the CF range were significantly younger at evaluation, had significantly more frequent symptoms consistent with CF lung disease, and were subsequently found to carry two cystic fibrosis transmembrane conductance regulator (CFTR) mutations more often.
Evaluation of CFTR function in the nasal epithelium of children with inconclusive CF diagnoses can be a useful diagnostic tool and help clinicians to individualize therapeutic strategy.