The insulin-like growth factors and growth disorders of childhood.

Specific lesions of the growth hormone (GH)/insulin-like growth factor (IGF) axis have been identified in humans, each of which has distinctive auxologic and biochemical features. Measures of circulating IGF-I are useful in diagnosing growth disorders in childhood and in evaluating response to GH therapy. Recombinant human IGF-I is an effective treatment of severe primary IGF deficiency, which is typical of patients with GH receptor defects (Laron syndrome). Such treatment has been limited to a few severely affected patients. Future studies will provide new insight into IGF-I as treatment and into the nature of growth disorders that involve the IGF axis.