Fragile X mental retardation gene 1 (FMR1) is the gene underlying the disorder Fragile X syndrome (FXS), which results in ID with 15%–30% of patients also displaying ASD phenotypes (Krawczun et al., 1985; Persico and Bourgeron, 2006; Kelleher and Bear, 2008; Santoro et al., 2012). This evidence concerns the gene FMR1 and fragile X syndrome.