Short stature associated with normal growth hormone and decreased somatomedin-C concentrations: response to exogenous growth hormone.

Two prepubertal males with low somatomedin-C concentrations in their sera, but normal growth hormone concentrations, had positive metabolic responses when human growth hormone was administered. An accelerated velocity of growth accompanied the long-term administration of growth hormone. This response was dependent upon the administration of exogenous hormone inasmuch as linear growth was subnormal both before and after administration of growth hormone. The extreme short stature in these individuals may be secondary to a biologically inactive growth hormone molecule that is immunologically reactive or to a decreased dose responsiveness of the cells that produce somatomedin when exposed to the usual concentrations of endogenous growth hormone.