Short Stature Caused by a Mutant Growth Hormone

The causes of growth hormone–dependent short stature are primary pituitary disease, pituitary deficiency due to hypothalamic dysfunction, and, less often, insensitivity to growth hormone. The prototypical syndrome of growth hormone insensitivity is Laron-type dwarfism, which is characterized by absent or defective growth hormone receptors. Kowarski et al. described two children with growth retardation resulting from biologically inactive growth hormone1; additional cases were reported subsequently.2–7 This disorder is characterized by high serum concentrations of immunoreactive growth hormone, low serum concentrations of insulin-like growth factor I (IGF-I), and increases in both serum IGF-I and linear growth after the administration of . . .