Cystic fibrosis with normal sweat chloride concentration: case report

• Autor(a) principal: Silva Filho,Luiz Vicente Ferreira da
• Data de Publicação: 2003
• Outros Autores: Bussamra,Maria Helena de Carvalho Ferreira, Nakaie,Cleyde Miriam Aversa, Adde,Fabíola Villac, Rodrigues,Joaquim Carlos, Raskin,Salmo, Rozov,Tatiana
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Revista do Hospital das Clínicas
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0041-87812003000500005
• topic: Cystic fibrosis; Atypical; Diagnosis; Sweat chloride; Mutations

Cystic fibrosis is a genetic disease usually diagnosed by abnormal sweat testing. We report a case of an 18-year-old female with bronchiectasis, chronic P. aeruginosa infection, and normal sweat chloride concentrations who experienced rapid decrease of lung function and clinical deterioration despite treatment. Given the high suspicion ofcystic fibrosis, broad genotyping testing was performed, showing a compound heterozygous with deltaF508 and 3849+10kb C->T mutations, therefore confirming cystic fibrosis diagnosis. Although the sweat chloride test remains the gold standard for the diagnosis of cystic fibrosis, alternative diagnostic tests such as genotyping and electrophysiologic measurements must be performed if there is suspicion of cystic fibrosis, despite normal or borderline sweat chloride levels.