HYPOTHYROIDISM AS AN INBORN ERROR OF METABOLISM

Abstract

CRETINISM in the United Kingdom is commonly sporadic and athyroidic; iodine intake is adequate but functional thyroid tissue is absent. In areas of endemic goiter, cretins are born with goiters; functional thyroid tissue is available initially but there is an insufficient supply of iodine to allow the thyroid gland to keep the fetus or infant in hormonal balance; the thyroid epithelium undergoes exhaustion atrophy after prolonged over-stimulation by thyrotropin. The pathogenesis of these two classic types of hypothyroidism is fairly clear. Within recent years, a third type of hypothyroidism has been encountered consequent upon the therapeutic use or the accidental ingestion of substances with a goitrogenic action such as para-amino-salicylic acid (1), thiocyanate (2), sulphonamides and the thiouracils (3, 4), the 2-mercaptoimidazoles (5) and resorcinol (6,7). From time to time hypothyroid children are seen who cannot be fitted into one of these well defined types. The literature contains several reports t...