Syndrome of generalized (peripheral tissue and pituitary) resistance to thyroid hormone

Generalized resistance to thyroid hormone (GRTH), or Refetoff syndrome, is a disease in which peripheral tissues show resistance to thyroid hormone. Three patients with this disease were investigated. Cases 1 and 2 involved identical 7-year-old female twins and case 3, a 5-year-old girl. All three patients had goiters, and cases 1 and 2 had sensorineural deafness. In all three, the blood levels of T4, free T4, and T3 were high, while the blood levels of TSH were normal or slightly elevated. The responses shown by blood levels of the thyroid hormone and TSH to administration of propylthiouracil and T3 suggest that the regulating mechanism in the hypothalamic-pituitary-thyroid system was functional. Upon administration of T3, no sign of hyperthyroidism was observed.