Two cases of the chromatin positive variety of ovarian dysgenesis (XO/XX mosaicism) associated with hGH deficiency and marginal impairment of other hypothalamic-pituitary functions.

Plasma hGH response to provocative tests (insulin-induced hypoglycaemia and arginine infusion) appears normal in Turner's syndrome. Two cases are reported of the chromatin positive variety of ovarian dysgenesis (XO/XX mosaicism) with unusual absence of plasms hGH response to provocative tests (arginine infusion, insulin-induced hypoglycaemia). Study of other pituitary functions supports the view that a hypothalamic-pituitary impairment is present in these cases. In fact, in these cases we observed low values of gonadotrophin excretion and limited responses of plasma ACTH and plasma corticosteroids to provocative tests (insulin-induced hypoglycaemia, metopyrone). Moreover, markedly abnormal plasma TSH response to TRF was observed in Case 2. The results are discussed with reference to the significance of this rare association.