title: The effect of parental allergy on childhood allergic diseases depends on the sex of the child.
abstract: BACKGROUND
  The parent-of-origin effect is important in understanding the genetic basis of childhood allergic diseases and improving our ability to identify high-risk children.
  
  
  OBJECTIVE
  We sought to investigate the parent-of-origin effect in childhood allergic diseases.
  
  
  METHODS
  The Isle of Wight Birth Cohort (n= 1456) has been examined at 1, 2, 4, 10, and 18 years of age. Information on the prevalence of asthma, eczema, rhinitis, and environmental factors was obtained by using validated questionnaires. Skin prick tests were carried out at ages 4, 10, and 18 years, and total IgE measurement was carried out at 10 and 18 years. Parental history of allergic disease was assessed soon after the birth of the child, when maternal IgE levels were also measured. Prevalence ratios (PRs) and their 95% CIs were estimated, applying log-linear models adjusted for confounding variables.
  
  
  RESULTS
  When stratified for sex of the child, maternal asthma was associated with asthma in girls (PR, 1.91; 95% CI, 1.34-2.72; P= .0003) but not in boys (PR, 1.29; 95% CI, 0.85-1.96; P= .23), whereas paternal asthma was associated with asthma in boys (PR, 1.99; 95% CI, 1.42-2.79; P< .0001) but not in girls (PR, 1.03; 95% CI, 0.59-1.80; P= .92). Maternal eczema increased the risk of eczema in girls (PR, 1.92; 95% CI, 1.37-2.68; P= .0001) only, whereas paternal eczema did the same for boys (PR, 2.07; 95% CI, 1.32-3.25; P = .002). Similar trends were observed when the effect of maternal and paternal allergic disease was assessed for childhood atopy and when maternal total IgE levels were related to total IgE levels in children at ages 10 and 18 years.
  
  
  CONCLUSIONS
  The current study indicates a sex-dependent association of parental allergic conditions with childhood allergies, with maternal allergy increasing the risk in girls and paternal allergy increasing the risk in boys. This has implications for childhood allergy prediction and prevention.
authors.affiliation: David Hide Asthma and Allergy Research Centre, Isle of Wight, United Kingdom. sha@soton.ac.uk
authors.forename: S Hasan
authors.initials: SH
authors.lastname: Arshad
authors.forename: Wilfried
authors.initials: W
authors.lastname: Karmaus
authors.forename: Abid
authors.initials: A
authors.lastname: Raza
authors.forename: Ramesh J
authors.initials: RJ
authors.lastname: Kurukulaaratchy
authors.forename: Sharon M
authors.initials: SM
authors.lastname: Matthews
authors.forename: John W
authors.initials: JW
authors.lastname: Holloway
authors.forename: Alireza
authors.initials: A
authors.lastname: Sadeghnejad
authors.forename: Hongmei
authors.initials: H
authors.lastname: Zhang
authors.forename: Graham
authors.initials: G
authors.lastname: Roberts
authors.forename: Susan L
authors.initials: SL
authors.lastname: Ewart
mesh_terms: D000293:Adolescent; D001249:Asthma / Q000453:epidemiology / Q000235:genetics* / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D004485:Eczema / Q000453:epidemiology / Q000235:genetics* / Q000276:immunology; D004777:Environment; D005260:Female; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000453:epidemiology / Q000235:genetics* / Q000276:immunology; D007073:Immunoglobulin E / Q000097:blood / Q000276:immunology; D007223:Infant; D008297:Male; D010290:Parents; D015995:Prevalence; D019655:Quantitative Trait, Heritable; D012044:Regression Analysis; D012220:Rhinitis / Q000453:epidemiology / Q000235:genetics* / Q000276:immunology; D012737:Sex Factors; D012882:Skin Tests; D011795:Surveys and Questionnaires; D014481:United States / Q000453:epidemiology
chemical_list: D007073:Immunoglobulin E