title: Does environment mediate earlier onset of the persistent childhood asthma phenotype?
abstract: OBJECTIVE
  We investigated the role of environmental and hereditary factors in determining whether persistent childhood wheezing phenotypes had an early or late onset.
  
  
  METHODS
  In a whole population birth cohort (n = 1456), children were seen at birth and at 1, 2, 4, and 10 years. At each visit, information was collected prospectively regarding wheeze prevalence and used to classify subjects into wheezing phenotypes. Information on genetic and environmental risk factors in early life was also obtained prospectively, and skin-prick testing to common allergens was performed at 4 years.
  
  
  RESULTS
  Early-onset persistent wheezers (n = 125) had wheeze onset in the first 4 years, still present at age 10, whereas late-onset persistent wheezers (n = 81) had wheeze onset after age 4 years that was still present at 10 years. Multivariate logistic regression analysis identified independent significance only for inherited factors (parental asthma, family history of rhinitis, eczema at 4 years, and atopic status at 4 years) in the development of late-onset persistent wheeze. However, low social class at birth, recurrent chest infections at 2 years, and parental smoking at 2 years plus inherited factors (eczema at 2 years; food allergy at 4 years; maternal asthma, sibling asthma, maternal urticaria, and atopic status at 4 years) demonstrated independent significance for early-onset persistent wheeze.
  
  
  CONCLUSIONS
  Inheritance seems to be of prime significance in the cause of persistent childhood wheeze. Environmental exposure in early life may combine with this tendency to produce an early onset of persistent wheeze. Absence of these environmental factors might delay but not prevent the onset of wheeze in children with atopic heredity.
authors.affiliation: The David Hide Asthma and Allergy Research Centre, St Mary's Hospital, Newport, Isle of Wight, United Kingdom.
authors.forename: Ramesh J
authors.initials: RJ
authors.lastname: Kurukulaaratchy
authors.forename: Sharon
authors.initials: S
authors.lastname: Matthews
authors.forename: S Hasan
authors.initials: SH
authors.lastname: Arshad
mesh_terms: D017668:Age of Onset; D001249:Asthma / Q000150:complications / Q000453:epidemiology / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D004485:Eczema / Q000150:complications; D004777:Environment; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000150:complications; D007223:Infant; D007231:Infant, Newborn; D016015:Logistic Models; D008297:Male; D010641:Phenotype; D015995:Prevalence; D012135:Respiratory Sounds / Q000209:etiology / Q000235:genetics*; D012220:Rhinitis / Q000150:complications; D012307:Risk Factors; D014028:Tobacco Smoke Pollution; D006113:United Kingdom / Q000453:epidemiology
chemical_list: D014028:Tobacco Smoke Pollution