Hyperthyroidism without Clinical Symptoms Found in Turner Syndrome During Human Growth Hormone Therapy

A nine-year-old Japanese girl with Turner syndrome (45, X/46, Xr (X)) showed poor GH secretion, normal response of TSH, and slightly increased secretion of LH and FSH with increased basic levels, after injection of insulin, TRH, and LH-RH respectively. Since then, r-hGH at 0.5 IU/kg/W has been given for five years under the diagnosis of pituitary dwarfism with Turner syndrome, and an increase of 26 cm in height has been obtained, though menstruation has not been observed till now. Autoimmune diseases such as diabetes mellitus, Addison's disease or thyroid dysfunction have not been observed, up to the age of 14 years. At 15 years, however, regular examination for side-effects of r-hGH revealed hyperthyroidism with 0.1 μU /ml of TSH, 15.7 μg/dl of T4, 4.22 ng/dl of free T4, positive thyroid test, positive microsome test, increased TSAb (1.4 μU/ml) and +32% of BMR, though she has not complained of any kind of clinical symptoms for six months.