A Child with Phenotypic Laron Dwarfism and Normal Somatomedin Levels

THE regulation of somatic growth is complex and requires a number of hormones, including growth hormone, somatomedin C (insulin-like growth factor I), thyroid hormones, insulin, and sex steroids. A new development in the area of human growth hormone is the discovery of circulating growth hormone–binding proteins,1 2 3 one of which appears to be a fragment of the growth hormone receptor.4 , 5 The precise role of the binding proteins in the regulation of growth is unknown, but they may be important, directly or indirectly, in growth, since the principal binding protein is absent in patients with Laron dwarfism6 , 7 and significantly decreased in African . . .