Levy H, Cannon CL, Asher D, García C, Cleveland RH, Pier GB, Knowles MR, Colin AA. Lack of correlation between pulmonary disease and cystic fibrosis transmembrane conductance regulator dysfunction in cystic fibrosis: a case report.
J Med Case Rep 2010;
4:117. [PMID:
20420703 PMCID:
PMC2873450 DOI:
10.1186/1752-1947-4-117]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2008] [Accepted: 04/26/2010] [Indexed: 11/17/2022] Open
Abstract
Introduction
Mutations in both alleles of the cystic fibrosis transmembrane conductance regulator gene result in the disease cystic fibrosis, which usually manifests as chronic sinopulmonary disease, pancreatic insufficiency, elevated sodium chloride loss in sweat, infertility among men due to agenesis of the vas deferens and other symptoms including liver disease.
Case presentation
We describe a pair of African-American brothers, aged 21 and 27, with cystic fibrosis. They were homozygous for a rare frameshift mutation in the cystic fibrosis transmembrane conductance regulator 3791delC, which would be expected to cause significant morbidity. Although 80% of cystic fibrosis patients are colonized with Pseudomonas aeruginosa by eight years of age, the older brother had no serum opsonic antibody titer to P. aeruginosa by age 13 and therefore would have failed to mount an effective antibody response to the alginate (mucoid polysaccharide) capsule of P. aeruginosa. He was not colonized with P. aeruginosa until 24 years of age. Similarly, the younger brother was not colonized with P. aeruginosa until age 20 and had no significant lung disease.
Conclusion
Despite a prevailing idea in cystic fibrosis research that the amount of functional cystic fibrosis transmembrane conductance regulator predicts clinical status, our results indicated that respiratory disease severity in cystic fibrosis exhibits phenotypic heterogeneity. If this heterogeneity is, in part, genetic, it is most likely derived from genes outside the cystic fibrosis transmembrane conductance regulator locus.
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