FMR1 and fragile X-associated tremor/ataxia syndrome: Finally, Fragile-X-associated tremor/ataxia syndrome (FXTAS) is a progressive neurological disorder associated to the premutation in the Fmr1 gene reported before (expansion up to 90 RGG repeats in the regulatory region) (Amiri et al., 2008; Kronquist et al., 2008).