title: Cystic fibrosis transmembrane conductance regulator mutations at a referral center for cystic fibrosis.
abstract: OBJECTIVE
  To determine the frequency of six mutations (F508del, G542X, G551D, R553X, R1162X, and N1303K) in patients with cystic fibrosis (CF) diagnosed, at a referral center, on the basis of abnormal results in two determinations of sweat sodium and chloride concentrations.
  
  
  METHODS
  This was a cross-sectional study involving 70 patients with CF. The mean age of the patients was 12.38 ± 9.00 years, 51.43% were female, and 94.29% were White. Mutation screening was performed with polymerase chain reaction (for F508del), followed by enzymatic digestion (for other mutations). Clinical analysis was performed on the basis of gender, age, ethnicity, pulmonary/gastrointestinal symptoms, and Shwachman-Kulczycki (SK) score.
  
  
  RESULTS
  All of the patients showed pulmonary symptoms, and 8 had no gastrointestinal symptoms. On the basis of the SK scores, CF was determined to be mild, moderate, and severe in 22 (42.3%), 17 (32.7%), and 13 (25.0%) of the patients, respectively. There was no association between F508del mutation and disease severity by SK score. Of the 140 alleles analyzed, F508del mutation was identified in 70 (50%). Other mutations (G542X, G551D, R553X, R1162X, and N1303K) were identified in 12 (7.93%) of the alleles studied. In F508del homozygous patients with severe disease, the OR was 0.124 (95% CI: 0.005-0.826).
  
  
  CONCLUSIONS
  In 50% of the alleles studied, the molecular diagnosis of CF was confirmed by identifying a single mutation (F508del). If we consider the analysis of the six most common mutations in the Brazilian population (including F508del), the molecular diagnosis was confirmed in 58.57% of the alleles studied.
authors: State University at Campinas, School of Medical Sciences, Department of Medical Genetics, Campinas, Brazil.
authors: Cyntia Arivabeni de Araújo Correia
authors: CA
authors: Coutinho
authors: Fernando Augusto de Lima
authors: FA
authors: Marson
authors: Antônio Fernando
authors: AF
authors: Ribeiro
authors: José Dirceu
authors: JD
authors: Ribeiro
authors: Carmen Silvia
authors: CS
authors: Bertuzzo
mesh_terms: D000293:Adolescent; D000328:Adult; D000483:Alleles; D001938:Brazil; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D003550:Cystic Fibrosis / Q000175:diagnosis / Q000235:genetics*; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000235:genetics*; D005260:Female; D006720:Homozygote; D006801:Humans; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D025202:Molecular Diagnostic Techniques / Q000379:methods; D009154:Mutation / Q000235:genetics; D016133:Polymerase Chain Reaction / Q000379:methods; D063728:Secondary Care Centers; D017384:Sequence Deletion / Q000235:genetics*; D012720:Severity of Illness Index; D055815:Young Adult
chemical_list: D019005:Cystic Fibrosis Transmembrane Conductance Regulator