A rare hyperthyroidism characterized by mild to severe hyperthyroidism, presence of goiter, absence of features of autoimmunity, frequent relapses while on treatment and a positive family history.

Graves disease (GRD) is an autoimmune disorder in which antibodies to the thyrotropin receptor (TSHR; 603372) result in constitutive activation of the receptor and increased levels of thyroid hormone. Wilkin (1990) reviewed endocrine disorders of hormone excess and hormone deficiency resulting from receptor autoimmunity. Genetic Heterogeneity of Graves Disease Susceptibility to Graves disease-1 (GRD1) has been mapped to chromosome 14q31. Other susceptibility loci for Graves disease include GRD2 (603388) on chromosome 20q13, GRDX1 (300351) on Xp11, and GRDX2 (see 300351) on Xq21.33-q22. Graves disease has also been mapped to several loci that confer susceptibility to autoimmune thyroid diseases, including Hashimoto thyroiditis (HT; 140300): AITD1 (608173) on 6p11; AITD2 (608174) on 5q31-q33; AITD3 (608175) on 8q24; AITD4 (608176) on 10q, and AITD5 (601941) on 18q21.

Generalized thyroid hormone resistance (GRTH) is characterized by elevated serum levels of free thyroid hormones with inappropriately elevated thyroid-stimulating hormone (TSH) as well as clinical and biochemical evidence of decreased thyroid hormone action. Affected individuals also show unresponsiveness to large doses of exogenous thyroid hormones (summary by Parrilla et al., 1991).

Abnormal thyroid hormone metabolism-3 (THMA3) is characterized by euthyroid hyperthyroxinemia, with elevated free T4 and reverse T3 levels, and normal TSH (see 188540) and free T3 levels. Patients also show low plasma selenium levels and reduced levels of stress-related selenoproteins (Schoenmakers et al., 2016; Geslot et al., 2021). For a discussion of genetic heterogeneity of abnormal thyroid hormone metabolism, see THMA1 (609698).