familial cretinism, a rare genetic disorder caused by an inborn error of metabolism resulting from an enzyme deficiency that interferes with thyroid hormone biosynthesis. Clinical manifestations include lethargy, stunted growth, and cognitive impairment. The condition is transmitted as an autosomal-recessive trait and is treated by early administration of thyroid hormone, if possible in utero, to reduce the abnormalities of mental development. See also cretinism.
