FMR1 and fragile X-associated tremor/ataxia syndrome: Although molecular links with cognitive phenotypes in the PM are less clear [2, 3], the severe cognitive atypicalities associated with FXTAS appear to be related to excess production of mRNA and are likely also associated with cellular toxicity [5, 13–15], and others have reported associations between FMRP and more subtle phenotypes as well [10, 16].