title: Uncertainty in the diagnosis of cystic fibrosis: possible role of in vivo nasal potential difference measurements.
abstract: The diagnosis of cystic fibrosis (CF) is not always certain, despite extensive clinical evaluation, multiple sweat chloride tests, and genotype analysis. We hypothesized that nasal transepithelial potential difference measurements have a useful role in this situation. In 11 patients without an established diagnosis of CF, results of simultaneous nasal potential difference (PD) and sweat chloride measurements were compared with those from control subjects, obligate CF heterozygotes, and patients with a confirmed diagnosis of CF. Two patients conformed to the PD profile for CF patients, whereas nine had values corresponding to those of the healthy control subjects. Subsequently the 5-thymidine (IVS8-5T) CF gene variant was identified in the two patients with abnormal PD measurements.
authors.affiliation: Department of Paediatrics, University of Toronto, Ontario, Canada.
authors.forename: D C
authors.initials: DC
authors.lastname: Wilson
authors.forename: L
authors.initials: L
authors.lastname: Ellis
authors.forename: J
authors.initials: J
authors.lastname: Zielenski
authors.forename: M
authors.initials: M
authors.lastname: Corey
authors.forename: W F
authors.initials: WF
authors.lastname: Ip
authors.forename: L C
authors.initials: LC
authors.lastname: Tsui
authors.forename: E
authors.initials: E
authors.lastname: Tullis
authors.forename: M R
authors.initials: MR
authors.lastname: Knowles
authors.forename: P R
authors.initials: PR
authors.lastname: Durie
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D002648:Child; D003550:Cystic Fibrosis / Q000175:diagnosis* / Q000235:genetics / Q000503:physiopathology; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000235:genetics; D010188:Exocrine Pancreatic Insufficiency / Q000175:diagnosis; D005260:Female; D006579:Heterozygote; D006801:Humans; D008297:Male; D008564:Membrane Potentials / Q000502:physiology; D009154:Mutation; D009297:Nasal Mucosa / Q000503:physiopathology*; D010641:Phenotype; D013542:Sweat / Q000737:chemistry
chemical_list: C505032:CFTR protein, human; D019005:Cystic Fibrosis Transmembrane Conductance Regulator