title: Both DQA1 and DQB1 genes are implicated in HLA-associated protection from type 1 (insulin-dependent) diabetes mellitus in a British Caucasian population.
abstract: Inherited susceptibility to Type 1 (insulin-dependent) diabetes mellitus is partly determined by HLA genes. It has been suggested that protection from disease may be conferred by HLA-DQB1 genes which encode molecules with aspartate at position 57. We investigated the contributions of HLA-DRB1, DQA1 and DQB1 genes to protection from disease. Restriction fragment length polymorphism and sequence specific oligonucleotide analysis in 156 British Caucasian Type 1 diabetic and 116 control subjects showed protection from disease was associated with DR2, DRw6 and DR7 haplotypes. The most protective DQA1 allele was DQA1*0102 which occurred on both DR2 and DRw6 haplotypes. The DQB1 alleles DQB1*0303, DQB1*0602 and DQB1*0603 were associated with protection, as was DQB1*0604, which encodes an Asp-57 negative DQ beta molecule. Heterozygosity for both protective and predisposing HLA markers was reduced in diabetic compared with control subjects. We conclude that both DQA1 and DQB1 genes are implicated in HLA-associated protection from Type 1 diabetes in this British Caucasian population. The overall structure of the DQ heterodimer is critical and DQ beta-Asp 57 is of secondary importance in determining protection from disease. The effect of protective HLA types may predominate over that of predisposing markers.
authors: Department of Medicine, University of Birmingham, UK.
authors: D A
authors: DA
authors: Cavan
authors: K H
authors: KH
authors: Jacobs
authors: M A
authors: MA
authors: Penny
authors: M A
authors: MA
authors: Kelly
authors: C
authors: C
authors: Mijovic
authors: D
authors: D
authors: Jenkins
authors: J A
authors: JA
authors: Fletcher
authors: A H
authors: AH
authors: Barnett
mesh_terms: D000328:Adult; D000483:Alleles; D000595:Amino Acid Sequence; D001483:Base Sequence; D003922:Diabetes Mellitus, Type 1 / Q000235:genetics / Q000276:immunology*; D020022:Genetic Predisposition to Disease; D006683:HLA-DQ Antigens / Q000235:genetics*; D059848:HLA-DQ alpha-Chains; D059866:HLA-DQ beta-Chains; D006684:HLA-DR Antigens / Q000235:genetics; D059811:HLA-DRB1 Chains; D000949:Histocompatibility Antigens Class II / Q000235:genetics; D006801:Humans; D007113:Immunity, Innate / Q000235:genetics; D008285:Major Histocompatibility Complex; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides; D016133:Polymerase Chain Reaction / Q000379:methods; D012016:Reference Values; D006113:United Kingdom; D044465:White People / Q000235:genetics*
chemical_list: D006683:HLA-DQ Antigens; D059848:HLA-DQ alpha-Chains; D059866:HLA-DQ beta-Chains; C069050:HLA-DQA1 antigen; C069051:HLA-DQB1 antigen; D006684:HLA-DR Antigens; D059811:HLA-DRB1 Chains; D000949:Histocompatibility Antigens Class II; D009838:Oligodeoxyribonucleotides