Precocious puberty associated with primary hypothyroidism in a mongol girl.

A mongol child suffereing from hypothyroidism who presented with precocious puberty is described. A presumptive diagnosis of idiopathic precocious puberty was first made and she was treated initially with medroxyprogesterone acetate, and later, with cyproterone acetate. The diagnosis of primary hypothyroidism was made late because of misleading results of protein bound iodine estimations. Subsequently, thyroid medication resulted in a prompt return to the normal range of the previously elevated levels of plasma gonadotrophins, thyroid stimulating hormone and plasma and urinary oestrogens, but the serum prolactin remained elevated for several months after therapy was begun.