FMR1 and fragile X syndrome: An alternative approach to explore in vivo functional links between mRNA toxicity, the type of toxicity (e.g. including toxic gain of function, as well as sense and anti-sense Repeat Associated non-ATG translation [Reviewed in Kraan et al. [2]]) and FMRP deficiency would be to use post-mortem brain tissues from FXS males, who had previously undergone formal assessments of intellectual functioning and autism.