Partial Primary Deficiency of Insulin-Like Growth Factor (IGF)-I Activity Associated with<i>IGF1</i>Mutation Demonstrates Its Critical Role in Growth and Brain Development

Abstract

This first report of mild deficiency of IGF-I activity demonstrates that the integrity of IGF-I signaling is important for normal growth and brain development. Molecular defects leading to partial loss of IGF-I activity may not be uncommon in patients born small for gestational age. The characterization of this complex phenotype and identification of such molecular defects have therapeutic implications, particularly now that, in addition to GH, recombinant IGF-I is available for clinical use.