DPA Polymorphisms in Normals, Type I Diabetics, and Patients with Graves’ Disease

Abstract

Among other organ-specific autoimmune diseases, Graves’ disease is generally associated with the serological DR3 specificity. However, the associations shown so far have not been as clear as with other autoimmune diseases and the relative risks have been calculated to be around 3 to 5. Furthermore, only 50 to 60% of patients possess the DR3 specificity. Therefore the actual disease susceptibility gene(s) are thought to be in linkage disequilibrium with genes in the human leukocyte antigen (HLA) region and might lie in the DP subregion or another on the short arm of chromosome 6. To investigate this association further at the genomic level we studied the structure of the HLA class II genes in patients with Graves’ disease, control subjects, diabetics, and families using restriction fragment length polymorphism (RFLP) analysis as well as serology.