In conclusion, this is a first study that provides evidence of an elevated expression of some of the FMR1 and ASFMR1 mRNA splicing isoforms is present in premutation carriers who develop FXTAS compared to those who remain symptom free and to controls, providing support for these measures as potential biomarkers for early identification and monitoring of disease progression. This evidence concerns the gene FMR1 and fragile X-associated tremor/ataxia syndrome.