title: Three-loci HLA haplotypes in Spanish celiac children and healthy subjects: estimation of linkage disequilibrium and haplotype frequencies.
abstract: OBJECTIVE
  The aim of this study was to compare the linkage disequilibrium parameters and the frequencies of the three-loci HLA haplotypes in children with celiac disease and in a control population within the same geographical area.
  
  
  METHODS
  A total of 38 celiac children were studied. HLA typing was performed by microlymphocytotoxicity assay using T and B cells separated by monoclonal antibody labeled immunomagnetic particles (IMB). Three-loci haplotype frequency (pABC) depend on each gene frequency (pA, pB, and pC), and a correction factor (delta) and takes the form: pABC = pA x pB x pC + delta ABC. The existence of a linkage disequilibrium was assessed by chi2 test using 2 x 2 x 2 contingency tables for gametic association.
  
  
  RESULTS
  There was a higher frequency of A1/B8/Cw7, A1/B8/DR3, A1/B8/DQ2, A19/B12/DQ2, B8/Cw7/DR3, B8/Cw7/DQ2, B8/DR3/DQ2, and B12/DR7/DQ2 in celiac children than in the control population.
  
  
  CONCLUSIONS
  From the comparative study of celiac and healthy population within the same area, we conclude that these three-loci haplotypes could determine genetic susceptibility to celiac disease.
authors.affiliation: Department of Paediatrics, University Hospital Lozano Blesa, University of Zaragoza Medical School, Spain.
authors.forename: M Y
authors.initials: MY
authors.lastname: Ruiz
authors.forename: J L
authors.initials: JL
authors.lastname: Olivares
mesh_terms: D000293:Adolescent; D000483:Alleles; D016022:Case-Control Studies; D002446:Celiac Disease / Q000235:genetics* / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D002874:Chromosome Mapping; D005787:Gene Frequency; D008040:Genetic Linkage; D006680:HLA Antigens / Q000235:genetics*; D006239:Haplotypes; D006801:Humans; D007223:Infant; D010641:Phenotype; D012016:Reference Values; D013030:Spain
chemical_list: D006680:HLA Antigens