title: HLA-DRB1, TAP2/TAP1, and HLA-DPB1 haplotypes in Finnish juvenile idiopathic arthritis: more complexity within the MHC.
abstract: This study further defines genetic susceptibility to JIA in the region centromeric to HLA-DRB1. DNA from 234 Finnish JIA nuclear families and 639 elderly Finnish control individuals was genotyped for five functional SNPs within the TAP2 and TAP1 loci ( approximately 200 kb centromeric of HLA-DRB1). Subsets of the controls (186) and patients (145) that had been previously typed for HLA-DRB1 were also genotyped by sequence for the HLA-DPB1 locus. Case/control and transmission disequilibrium test (TDT) methods revealed an association with the DPB1(*)030101 allele for JIA (OR 2.3, 95% CI 1.5-3.5). Notably, a detailed haplotypic analysis of the TAP2/TAP1 loci and their interaction with the HLA-DPB1(*)030101 and DRB1(*)08 and (*)11 alleles showed a variety of over-represented and under-represented TAP2/TAP1 haplotypes not evident in the single marker analysis. The strongest effect was observed in the polyarticular RF negative JIA subgroup for the 2-2-1-2-1 TAP2/TAP1 haplotype (TAP2B and TAP1A alleles) which showed an independent effect from both DRB1(*)08 and (*)11 (P<0.000003) and DPB1(*)030101 (P=0.02). We have provided evidence that the extended haplotypes (including HLA-DRB1, TAP2/TAP1, and HLA-DPB1) of pauciarticular and polyarticular RF negative disease are distinct. This observation may have implications for functional etiological differences between the pauciarticular and polyarticular JIA patients.
authors.affiliation: Rowe Program in Human Genetics and Molecular Medicine, Department of Biological Chemistry, University of California, Davis 95616, USA. jarunstadler@ucdavis.edu
authors.forename: J A
authors.initials: JA
authors.lastname: Runstadler
authors.forename: H
authors.initials: H
authors.lastname: Säilä
authors.forename: A
authors.initials: A
authors.lastname: Savolainen
authors.forename: M
authors.initials: M
authors.lastname: Leirisalo-Repo
authors.forename: K
authors.initials: K
authors.lastname: Aho
authors.forename: E
authors.initials: E
authors.lastname: Tuomilehto-Wolf
authors.forename: J
authors.initials: J
authors.lastname: Tuomilehto
authors.forename: M F
authors.initials: MF
authors.lastname: Seldin
mesh_terms: D000071181:ATP Binding Cassette Transporter, Subfamily B, Member 2; D000071450:ATP Binding Cassette Transporter, Subfamily B, Member 3; D018528:ATP-Binding Cassette Transporters / Q000235:genetics*; D000368:Aged; D001171:Arthritis, Juvenile / Q000235:genetics*; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D002648:Child; D002675:Child, Preschool; D016001:Confidence Intervals; D005260:Female; D005387:Finland; D006682:HLA-DP Antigens / Q000235:genetics*; D059868:HLA-DP beta-Chains; D006684:HLA-DR Antigens / Q000235:genetics*; D059811:HLA-DRB1 Chains; D006239:Haplotypes / Q000235:genetics*; D006801:Humans; D008285:Major Histocompatibility Complex / Q000235:genetics*; D008297:Male; D016017:Odds Ratio
chemical_list: D000071181:ATP Binding Cassette Transporter, Subfamily B, Member 2; D000071450:ATP Binding Cassette Transporter, Subfamily B, Member 3; D018528:ATP-Binding Cassette Transporters; D006682:HLA-DP Antigens; D059868:HLA-DP beta-Chains; C071170:HLA-DPB1 antigen; D006684:HLA-DR Antigens; D059811:HLA-DRB1 Chains; C073119:TAP1 protein, human; C071692:TAP2 protein, human