title: Ethnicity impacts the cystic fibrosis diagnosis: A note of caution.
abstract: BACKGROUND
  The diagnosis of Cystic Fibrosis (CF) is by consensus based on the same parameters in all patients, yet the influence of ethnicity has only scarcely been studied. We aimed at elucidating the impact of Asian descent on the diagnosis of CF.
  
  
  METHODS
  We performed a retrospective analysis of the CFTR2 and UK CF databases for clinical phenotype, sweat chloride values and CFTR mutations and compared the diagnostic characteristics of Asian to non-Asian patients with CF.
  
  
  RESULTS
  Asian patients with CF do not have a worse clinical phenotype. The repeatedly reported lower FEV1of Asian patients with CF is attributable to the influence of ethnicity on lung function in general. However, pancreatic sufficiency is more common in Asian patients with CF. The diagnosis of CF in people with Asian ancestry is heterogeneous as mean sweat chloride values are lower (92±26 versus 99±22mmol/L in controls) and 14% have sweat chloride values below 60mmol/L (versus 6% in non-Asians). Also, CFTR mutations differ from those in Caucasians: 55% of British Asian patients with CF do not have one mutation included in the routine newborn screening panel.
  
  
  CONCLUSIONS
  Bringing together the largest cohort of patients with CF and Asian ethnicity, we demonstrate that Asian roots impact on all three CF diagnostic pillars. These findings have implications for clinical practice in the increasingly ethnically diverse Western population.
authors.affiliation: Pediatric Pulmonology, University Hospitals Leuven, Leuven, Belgium; Organ Systems, KU Leuven, Leuven, Belgium. Electronic address: barbara.bosch@uzleuven.be.
authors.forename: Barbara
authors.initials: B
authors.lastname: Bosch
authors.affiliation: NIHR Specialist Respiratory Biomedical Research Unit, Royal Brompton and Harefield NHS Foundation Trust and Imperial College, London, UK.
authors.forename: Diana
authors.initials: D
authors.lastname: Bilton
authors.affiliation: Pulmonary & Critical Care Medicine, Johns Hopkins University, Baltimore, USA; McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University, Baltimore, USA.
authors.forename: Patrick
authors.initials: P
authors.lastname: Sosnay
authors.affiliation: McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University, Baltimore, USA.
authors.forename: Karen S
authors.initials: KS
authors.lastname: Raraigh
authors.affiliation: Cystic Fibrosis Canada, Toronto, Canada.
authors.forename: Denise Y F
authors.initials: DYF
authors.lastname: Mak
authors.affiliation: Human Nutrition, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ishiguro
authors.affiliation: Research Department, Dutch Cystic Fibrosis Foundation, Baarn, The Netherlands.
authors.forename: Vincent
authors.initials: V
authors.lastname: Gulmans
authors.affiliation: Belgium Cystic Fibrosis Registry (BMR-RBM), Scientific Institute of Public Health (WIV-ISP), Brussels, Belgium.
authors.forename: Muriel
authors.initials: M
authors.lastname: Thomas
authors.affiliation: Pediatric Pulmonology, University Hospitals Leuven, Leuven, Belgium.
authors.forename: Harry
authors.initials: H
authors.lastname: Cuppens
authors.affiliation: University of Lisboa, Faculty of Sciences, BioISI - Biosystems & Integrative Sciences Institute, Lisboa, Portugal.
authors.forename: Margarida
authors.initials: M
authors.lastname: Amaral
authors.affiliation: Pediatric Pulmonology, University Hospitals Leuven, Leuven, Belgium.
authors.forename: Kris
authors.initials: K
authors.lastname: De Boeck
mesh_terms: D000293:Adolescent; D000328:Adult; D044466:Asian People / Q000235:genetics / Q000706:statistics & numerical data; D002675:Child, Preschool; D002712:Chlorides / Q000032:analysis; D003550:Cystic Fibrosis / Q000175:diagnosis / Q000208:ethnology / Q000235:genetics / Q000503:physiopathology; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000235:genetics*; D005260:Female; D005820:Genetic Testing; D006801:Humans; D007231:Infant, Newborn; D008176:Lung Volume Measurements / Q000379:methods; D008297:Male; D009154:Mutation; D015997:Neonatal Screening / Q000941:ethics / Q000379:methods; D010179:Pancreas / Q000503:physiopathology; D012042:Registries / Q000706:statistics & numerical data; D013542:Sweat / Q000737:chemistry*; D006113:United Kingdom / Q000453:epidemiology
chemical_list: D002712:Chlorides; D019005:Cystic Fibrosis Transmembrane Conductance Regulator
keywords: Asian ethnicity; CFTR2; Cystic fibrosis diagnosis; Newborn screening panel; UK CF registry