The protein encoded by FMR1, FMRP, is an RNA-binding protein involved in translational repression, synaptic maturation, dendritic mRNA localization and nucleoplasmic shuttling of mRNA (Antar et al. 2005; Brown et al. 1998; Weiler et al. 1997) lending support to the idea that its aberrant expression contributes to the intellectual disabilities (ID) associated with FXS (Hinton et al. 1991; Irwin et al. 2000; O’Donnell and Warren, 2002). This evidence concerns the gene FMR1 and Intellectual disability.