Specific DNA Polymorphisms in the DQ Alpha Region of Patients with Graves’ Disease and Hashimoto’s Thyroiditis

Abstract

Amongst other organ-specific autoimmune diseases Graves’ disease and Hashimoto’s thyroiditis are generally associated with certain serological HLA DR specificities (DR3 and DR4 and/or 5 respectively). 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 3–4. Therefore the actual disease susceptibility gene(s) are thought to be in linkage disequilibrium with genes in the HLA D region and might lie in the DQ subregion 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 and Hashimoto’s thyroiditis using RFLP (restriction fragment length polymorphism) analysis. Patients and controls were also studied with serological methods.