The fragile X syndrome: bridging the gap from gene to behavior

Fragile X syndrome is a genetic condition caused by a mutation, a cytosine- guanine-guanine triplet expansion, on the X chromosome. The behavioral phen otype includes characteristic developmental, cognitive, and psychiatric dis orders, including childhood abnormalities of attention and social anxiety. Recent progress has been made in describing the molecular biology of the mu tation, the neurocellular consequences of absent or decreased fragile X men tal retardation protein, the behavioral phenotype, and the structural and f unctional brain abnormalities in fragile X syndrome. Recent research in fra gile X syndrome studies has combined advances in molecular biology with a w ell-validated set of cognitive, adaptive, behavioral measures, and function al neuroimaging paradigms. (C) 2001 Lippincott Williams & Wilkins.