Congenital hypothyroidism with impaired thyroid response to thyrotropin.

Abstract

An eight-year-old boy had congenital hypothyroidism and severely retarded development. The thyroid gland was not enlarged, but there was cell hypertrophy of the follicular epithelial elements. Laboratory findings included low serum concentration of protein-bound iodine, high biologically active thyrotropin, normal 131I uptake, no response to thyrotropin either in vivo or in metabolism of glucose by thyroid tissue slices, absence of thyroglobulin from the biopsy and presence in the gland of a dense, insoluble iodoprotein and a light, soluble iodoprotein that was not iodoalbumin. Most of the circulating protein-bound iodine was not soluble in butanol. The hypothesis offered is that the fundamental defect in this gland is an impaired ability to respond to stimulation by thyrotropic hormone in two organ-specific and possibly coupled modes: cell division (growth) and synthesis of thyroglobulin.