FMR1 and fragile X-associated tremor/ataxia syndrome: Aside from obviously elevated FMR1 mRNA levels, reduced FMRP expression, and intranuclear inclusion formation, mouse models of FXTAS also exhibit abnormal dendritic spine morphology, impaired motor coordination, and cognitive deficits, recapitulating many features of FXTAS patients (Bontekoe et al., 2001; Willemsen et al., 2003; Entezam et al., 2007; Hunsaker et al., 2009; Hukema et al., 2015).