Familial Graves' disease associated with type 1 diabetes.

A 59-year-old woman was diagnosed as having Graves' disease and type 1 diabetes. DNA molecular HLA typing detected DRB1(*)0405 and DQB1(*)0401, as well as the haplotypes of DRB1(*)0901-DQB1(*)0303. We also performed polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) to identify allele variations of other loci. The patient's son also manifested Graves' disease and type 1 diabetes, with both cases having strikingly homologous clinical features. Familial clustering of Graves' disease and type 1 diabetes, and their tendency to occur together along with a similar clinical course suggest that their etiology may involve shared genetic factors.