Autoimmune polyglandular syndrome Type 3 and growth hormone deficiency.

The simultaneous occurrence of prepubertal Graves' disease, type 1 Diabetes Mellitus (DM), and Growth hormone deficiency (GHD) is uncommon. GHD has been reported in Autoimmune Polyglandular Syndrome (APS) Type 1 and Type 2 but not in APS Type 3. We report a 3-yr-old boy who presented simultaneously with type 1 DM and Graves' disease. After he developed urticarial rash to Propylthiouracil and Methimazole with persistent thyrotoxicosis, he received 8 millicuries of (131)I at 5 yr of age. We diagnosed GHD at age 8 yr 8 months because of growth deceleration (from 95 to 25%) and abnormal growth rate (3 cm/yr) despite euthyroidism, fair glycemic control, and normal weight gain. Both insulin-like growth factor (IGF) 1 (90 ng/mL; normal 113-261 ng/mL) and IGFBP3 (1.3 mcg/mL; normal 2.1-4.2 mcg/mL) levels were low and peak growth hormone level measured by RIA was 5.2 ng/mL after L-Dopa and insulin tolerance test. The rest of his pituitary functions and magnetic resonance imaging of the pituitary gland were normal. Growth hormone treatment (0.3 mg/kg/wk) was administered at 8 yr 9 months until near final adult height (FAH). Near FAH (172 cm) was close to midparental target height of 180 cm. GHD may be a component of all APS even though it is rare. Growth in treated children with Graves' disease should be followed closely as catch down growth below genetic height potential may be a harbinger of underlying GHD.