Fragile X syndrome: new developments

Molecular and clinical studies have demonstrated a spectrum of involvement in fragile X syndrome, such that some individuals may have only emotional problems and others may have more significant cognitive involvement. The new fragile X mental retardation 1 protein studies have been helpful in assessing milder forms of involvement and have detected some individuals with the premutation who are significantly affected. The fragile X mental retardation 1 protein appears to be a translation regulator and one of the first proteins produced in the neuron with metabotropic glutamate receptor stimulation. It is hypothesized that fragile X mental retardation 1 protein is necessary for the process of pruning and maturation of selected synapses, perhaps through the regulation of translation of other messages. Curr Opin Psychiatry 12:573-578. (C) 1999 Lippincott Williams & Wilkins.