title: Arginine at position 74 of the HLA-DR beta1 chain is associated with Graves' disease.
abstract: Graves' disease (GD) is associated with HLA-DR3 (DRB1*03) in Caucasians, but the exact amino-acid sequence in the DR beta1 chain conferring susceptibility to GD is unknown. Therefore, the aim of our study was to identify the critical sequence among the HLA-DRB1 amino-acid residues occupying the peptide-binding pocket, which conferred susceptibility to GD. We sequenced the HLA-DRB1 locus in 208 Caucasian GD patients and 149 Caucasian controls. Sequence analysis showed an increased frequency of DR beta-Arg-74 in GD patients compared to controls (41.8 and 13.4%, respectively; P=2.3 x 10(-8), OR=4.6). Moreover, subset analyses showed that DR beta-Arg-74 was also significantly more frequent in the HLA-DR3 negative GD patients than in controls (7.6 vs 0.8%, P=0.02, OR=10.5), suggesting that the association with DR beta-Arg-74 is independent of the association with HLA-DR3. Structural modeling studies demonstrated that the change at position 74 from the neutral amino acids Ala or Gln to the positively charged amino-acid Arg significantly modifies the three-dimensional structure of the DR peptide-binding pocket. Our results suggested that structural heterogeneity of the DR beta-chain peptide-binding pocket P4 at residue 74 predispose some at risk individuals to GD.
authors.affiliation: Division of Endocrinology, Diabetes, and Bone Diseases, Department of Medicine, Mount Sinai School of Medicine, New York, NY 10029, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Ban
authors.forename: T F
authors.initials: TF
authors.lastname: Davies
authors.forename: D A
authors.initials: DA
authors.lastname: Greenberg
authors.forename: E S
authors.initials: ES
authors.lastname: Concepcion
authors.forename: R
authors.initials: R
authors.lastname: Osman
authors.forename: T
authors.initials: T
authors.lastname: Oashi
authors.forename: Y
authors.initials: Y
authors.lastname: Tomer
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000483:Alleles; D001120:Arginine / Q000737:chemistry / Q000235:genetics*; D016022:Case-Control Studies; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D006111:Graves Disease / Q000453:epidemiology / Q000235:genetics*; D006684:HLA-DR Antigens / Q000235:genetics*; D059811:HLA-DRB1 Chains; D006801:Humans; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D044465:White People
chemical_list: D006684:HLA-DR Antigens; D059811:HLA-DRB1 Chains; D001120:Arginine