ABSTRACT
Intranuclear receptors mediate the actions of thyroid hormone. Mutations in the genes coding for these receptors may attenuate the effects of the hormone. Since the first description of the syndrome of reduced responsiveness to thyroid hormone a large number of mutations and a major deletion in one of the two genes coding for these receptors have been described. A wide variety of findings have appeared among the subjects with Generalized Resistance To Thyroid Hormone (GRTH). Some have been distinctly hypothyroid, and, rarely, some have had the typical features of congenital hypothyroidism, with neonatal jaundice, deafness, nystagmus, delayed dentition and bone maturation, delayed growth and learning, diminished attention span, and mental retardation. The important aspect of treatment of patients with GRTH is to avoid medications or procedures that have no need or promise. A diagnosis of thyrotoxicosis is a trap that one falls easily into, and must be avoided.
