Mice where the Fmr1 gene has been knocked out (Fmr1-KO; The Dutch-Belgian Fragile X Consortium et al., 1994) exhibit some phenotypic features similar to humans with FXS such as hypersensitivity, hyperactivity, diminished attentive capacity and anxiety (Kooy et al., 2017). This evidence concerns the gene FMR1 and fragile X syndrome.