[Experimental therapeutic models for fragile X syndrome]

Fragile X syndrome is the most frequent form of familial mental retardation. The disease is caused by the absence of the function of the FMR1 gene product (FMRP). FMRP is a mRNA binding protein but the mechanism by which FMRP inactivation leads to the cognitive deficits in fragile X patients is still unknown. There is no effective specific treatment for the disease. The genetics of the fragile X syndrome suggest that gene therapy may eventually be able to provide a cure for the disease. However several different approaches are also being investigated by many different research laboratories. The search for an effective therapy for fragile X patients will be facilitated by a better understanding of the pathophysiology of the disease. This requires research into many different areas of biology including protein replacement therapy, gene reactivation, transcriptional regulation, neuronal activity enhancement and neuroprotection, nutritional intervention, regulation of neurotransmission and synapse regeneration. All these approaches can be investigated using animal models of the fragile X syndrome, before being used to develop effective treatment for fragile X patients. Although there is still no cure for the fragile X syndrome, the symptoms of the disease can be treated using an integrated approach where the different interventions are supported by a specific team. All of these approaches are providing new insights into both the treatment of fragile X patients and our understanding of the pathophysiology of the disease. Until a cure is found, an integrated approach to intervention is the best way to minimise or avoid some of the manifestations associated with the fragile X syndrome.