title: Lack of association of HLA class II alleles with peanut allergy.
abstract: BACKGROUND
  Peanut allergy is a common and severe phenotype of food allergy with a strong genetic component; HLA class II polymorphisms are attractive candidate genes for this disorder.
  
  
  OBJECTIVE
  To determine possible genotypic associations of HLA class II with peanut allergy and attempt replication of previously reported associations.
  
  
  METHODS
  Sibling pairs discordant for peanut allergy were genotyped (low resolution) by polymerase chain reaction-based methods to 7 DQ and 18 DR allele groups. A chi2 analysis was undertaken against sibling controls with statistical adjustment for multiple analyses.
  
  
  RESULTS
  Seventy-three children with confirmed peanut allergy (mean age, 6.5 years; male, 72%; asthma, 58%; atopic dermatitis, 62%; allergic rhinitis, 67%; other food allergies, 41%) and 75 of their siblings who eat peanut (mean age, 8 years; male, 52%; asthma, 12%; atopic dermatitis, 22%; allergic rhinitis, 37%; other food allergy, 7%) were genotyped. Distribution of DQ7 (29% of children with peanut allergy vs 47% sibling controls) was statistically significantly different (P = .04) before statistical correction for multiple comparisons was made by multiplying them by the number of alleles tested (and not statistically significant after correction; P = .30). Distribution of DR11 was nearly statistically significant without statistical adjustment (26% with peanut allergy vs 41% of sibling controls; P = .07; corrected P = 1.3). Alleles that were previously reported to have a weak association with peanut allergy (DRB1 *03, *08; DQB1 *0302, *04) were not verified in this cohort (unadjusted P > .44).
  
  
  CONCLUSIONS
  We could not establish an association between the HLA class II alleles evaluated in this cohort of sibling pairs discordant for peanut allergy.
authors.affiliation: The Elliot and Roslyn Jaffe Food Allergy Institute, Division of Allergy and Immunology, Department of Pediatrics, Mount Sinai School of Medicine, New York, New York, USA.
authors.forename: Wayne G
authors.initials: WG
authors.lastname: Shreffler
authors.forename: Zachary
authors.initials: Z
authors.lastname: Charlop-Powers
authors.forename: Scott H
authors.initials: SH
authors.lastname: Sicherer
mesh_terms: D002648:Child; D004247:DNA / Q000032:analysis / Q000235:genetics; D005260:Female; D020022:Genetic Predisposition to Disease; D006683:HLA-DQ Antigens / Q000145:classification / Q000235:genetics*; D006684:HLA-DR Antigens / Q000145:classification / Q000235:genetics*; D006801:Humans; D008297:Male; D021183:Peanut Hypersensitivity / Q000235:genetics*
chemical_list: D006683:HLA-DQ Antigens; D006684:HLA-DR Antigens; D004247:DNA