ESPE Abstracts

Background: Laron syndrome (LS), (OMIM#262500) is a rare recessively inherited disease caused by deletions or mutations of the GH receptor, and is characterized by low or undetectable serum IGF-I. This deficiency leads to a series of metabolic abnormalities including of the proteins.

Subjects & Method: This study presents for the first time the amino-acid analysis of two untreated and one IGF-I treated LS patients using the LC-MS/MS method (Waters TQS Micro system).

Results: The main findings are summarized in the following Table 1. The untreated LS patients have an increase in the plasma Aspartic, Alla-isoleucine, Carnosine, Aminoadipic and Sarcosine acids, while Glutamine was decreased compare to the LS treated patient and normal control. We also found that both the untreated and treated LS patients have an elevation in plasma Lysine (244 Isomer) and Ornithine acids, compared to the control.

Conclusions: Congenital IGF-I deficiency alters the plasma amino acid composition changes which are partial reversible by long term IGF-I therapy.