hypothyroidism that can be due to endemic congenital goiter; nonendemic cases are usually due to defective thyroidal embryogenesis, defective hypothalamopituitary function, congenital defects in thyroid hormone synthesis or action, or intrauterine exposure to goitrogenic agents. SYN: Brissaud infantilism, congenital myxedema, dysthyroidal infantilism, hypothyroid dwarfism, hypothyroid infantilism, infantile myxedema, myxedematous infantilism.