Macroorchidism and fragile X in mentally retarded males
An infant with progressive obesity and bulimia present from birth was first seen by us at the age of 1 year and has now been followed for 3 years. He grew consistently along the 90th percentile with slight bone age retardation. He had enlarged testes for age (4ml). His motor and mental development was slightly retarded. The main laboratory findings were: a) persistently low basal prolactin levels and very low response (peaks < 5 ng/ml) to TRH, metoclopropamide, 2-deoxyglucose and insulin hypoglycemia, b) low-normal serum thyroxin (4.9-6.9 μg/dl) with subnormal responses of TSH to TRH (peaks 3.6 and 7 μU/ml), c) exaggerated response of FSH to LH-RH (peaks 4.0, 4.5, 8.0 mU/ml) and exaggerated testosterone response (300 ng/dl) after HCG (1500 Ux3). CNS investigation which included a CAT-scan revealed no pathology. It is concluded that this child has a hypothalamic-pituitary disturbance not hitherto described. The endocrine findings can be explained by an oversecretion of LH-RH and PIF and lowered secretion of TRH, in addition to a stimulation of the hypothalamic appetite center.Z. Laron - Established Investigator of the Chief Scientist's Bureau Ministry of Health.