Thyroid autoimmune disease in a large Newfoundland family: the influence of HLA.

Ninety-eight members of a large Newfoundland family, seven of whose members over three generations suffered from Graves' disease, were studied with respect to the mode of transmission of the disease and its association with HLA. Compared to Newfoundland communities of similar size and geographical location, very little consanguinity was documented in this family. The susceptibility to Graves' disease appeared to be inherited as a dominant with a variable degree of expressivity; the degree of expressivity being determined by the female sex. In part of the pedigree, the susceptibility to Graves' disease entered the family with a wife. Three of her offspring who subsequently developed Graves' disease shared with her the haplotype A9, Bw16. Of the three remaining affected family members, two shared the haplotype A1, B8, whereas the third carried the haplotypes Aw32,b8; a9,bw16. Graves' disease could be associated with either of these two haplotypes in the last individual. This study shows that the susceptibility to Graves' disease is inherited associated with HLA and that whereas the disease susceptibility gene for Graves' disease is in linkage disequilibrium with HLA-B8 in Caucasians, it can be randomly associated with other HLA-B antigens.