Fragile X–associated tremor ataxia syndrome (FXTAS) defined by fragile X mental retardation 1 (FMR1) premutation, cerebellar ataxia, intentional tremor, middle cerebellar peduncle hyperintensities in MRI and peripheral neuropathy (Jacquemont et al., 2003; Apartis et al., 2012). The gene discussed is FMR1; the disease is fragile X-associated tremor/ataxia syndrome.