Fragile X syndrome, the leading known inherited cause of mental retardation and developmental disabilities, is caused by a trinucleotide repeat expansion in the 5' untranslated region of the FMR1 gene in Xq27.3 Research during the pat five years has documented the genetic abnormalities that cause this syndrome and described the impairments, disabilities, and disadvantages associated with it. Future research is needed to foucs on genetics and neurobiology, screening and early identification, biomedical treatments, psychoeducational interventions, and family adaptation and support. © 1995 Wiley-Liss, Inc.
