FMR1-AS1 and fragile X-associated tremor/ataxia syndrome: Another highly similar splicing isoform that lacks 131 bp near the TSS (ASFMR1-Iso131bp) was also higher expressed in PM carriers independently of a FXTAS diagnosis compared to controls, with a trend to be correlated with tremor intensity as measured in a series of tasks involving postural and intentional tremor, postural sway, manual coordination, and reaction time [102].