Natural history of the classical form of primary growth hormone (GH) resistance (Laron syndrome)

A description of the clinical, biochemical and endocrinological features of the classical form of the syndrome of primary growth hormone (GH) resistan ce (Laron syndrome) is presented including the progressive changes during f ollow-up from infancy into adulthood. The main diagnostic features are: sev ere growth retardation, acromicria, small gonads and genitalia, and obesity . Serum GH levels are elevated and insulin-like growth factor-I (IGF-I) val ues are low and do not rise upon stimulation by exogenous hGH, The pathogen esis of this syndrome is due to various molecular defects from exon deletio n to nonsense, frameshift, splice and missense mutations in the GH receptor (GB-R) gene or in its post-receptor pathways.