In 1991, the gene responsible for the Fragile X syndrome, FMR1, was first identified. Since then, important advances have been made in understanding the genetic inheritance of this gene, its regulation and the potential roles of its protein product, FMRP.
Fragile X research has greatly benefited from animal models that have a deletion of the Fmr1 gene: Fmr1 knockout (KO) animals. Mouse models of Fragile X have been extremely useful in guiding research efforts, but they may not recapitulate the heterogeneity of symptoms and severity that are manifest in humans.
But mice may not recapitulate the range of symptoms and severity seen in humans. Several therapies based on mouse models have been developed, which have not been as effective as hoped when treatment is applied to human patients. Additional approaches are needed.
