Purpose: Fragile X-associated tremor/ataxia syndrome (FXTAS) was originally defined as tremor, ataxia, cognitive decline, and parkinsonism in individuals who carry between 55 and 200 CGG repeats in the promoter region of the fragile X mental retardation 1 (FMR1) gene. Here, FMR1 is linked to fragile X-associated tremor/ataxia syndrome.