TG and thyroid hormone resistance syndrome: Thyroid hormone resistance (RTH) (mim # 188570) is a rare autosomal dominant genetic disorder characterized by a reduced response in target tissues to circulating thyroid hormone.[1–5] First reported in 1967 by Refetoff, DeWind, and DeGroot, RTH has an incidence of 1 in 40,000 to 50,000 with an equal sex preponderance.