The disorder is caused by transcriptional shutdown in neurons of the FMR1 gene product, the Fragile X mental retardation protein
. Fragile X, a childhood neurological disorder that afflicts approximately 135,000 individuals in the U.S., is characterized by widespread loss of synaptic connections and occurs early in the neurological development process.
Fragile X mental retardation protein
(FMRP) is widely expressed in neurons and glia in the brain and acts as an "interactor" regulating ribosome stalling, translational control, and synaptic plasticity in brain circuits [1-3].
Fragile X syndrome results from mutations in the FMR1 gene, which blocks expression of the Fragile X Mental Retardation Protein
(FMRP), an important protein in GABA synthesis.
In Fragile X syndrome, the gene coding for a protein that plays a critical role in typical brain development and function (called the "fragile X mental retardation protein
," or FMRP) has a "full mutation" that virtually abolishes the manufacturing of FMRP.