Fragile X syndrome: An aging perspective

Fragile X-associated tremor/ataxia syndrome: an aging face of the fragile X gene.

F ragile X–associated tremor/ataxia syndrome (FXTAS) is a late-adult–onset neurodegenerative disorder affecting primarily male (and occasionally female) carriers of a premutation expansion (55-200 CGG repeats) of the fragile X mental retardation 1 gene (FMR1). FXTAS is principally characterized as a movement disorder with progressive intention tremor and gait ataxia, with more variable associat...

Molecular mechanisms of fragile X syndrome: a twenty-year perspective.

Fragile X syndrome (FXS) is a common form of inherited intellectual disability and is one of the leading known causes of autism. The mutation responsible for FXS is a large expansion of the trinucleotide CGG repeat in the 5' untranslated region of the X-linked gene FMR1. This expansion leads to DNA methylation of FMR1 and to transcriptional silencing, which results in the absence of the gene pr...

The fragile X syndrome.

We have begun to appreciate that the extent of this disorder is much wider than merely mental retardation. It is also a common cause of learning and emotional problems in mildly affected female carriers with normal IQs. These children present an enormous challenge to all child-care providers, be they in medicine, education, or in various therapy disciplines. Early identification is essential, a...

Fragile X syndrome.

Fragile X syndrome

Fragile X syndrome occurs as a result of a mutation of the fragile X mental retardation 1 (FMR1) gene on the bottom of the X chromosome (Pic. 1), which encodes fragile X mental retardation protein (FMRP). This protein, most commonly found in the brain, is essential for normal cognitive development and female reproductive function. The CGG triplet that means gene segment consisting of a cytosine...