arrested physical and mental development with dystrophy of bones and soft tissues, due to congenital lack of
thyroid gland secretion from hypofunction or absence of the gland. Affected children have a large head, short limbs, puffy eyes, coarse hair, a round abdomen, a thick and protruding tongue with drooling, excessively dry skin, lack of coordination, and mental retardation. Thyroid deficiency that is acquired or seen in adults is called
myxedema. Administration of
thyroid hormone medication, which must be continued for life, can result in normal growth and mental development of these children. If untreated, however, they will become permanently dwarfed, probably mentally retarded, and sterile.