FMR1-AS1 and fragile X-associated tremor/ataxia syndrome: In this study, we investigated the correlation between levels of mRNA expression of the FMR1 locus (mRNA expression levels of the FMR1 and of the ASFMR1 genes and of the ASFMR1 131 bp splice isoform) and a selected group of measures in the CATSYS associated with the core symptoms of FXTAS (tremor and balance) in the non-FXTAS premutation carriers compared to controls.