FMR1 and fragile X syndrome: The most favored model organism, the mouse, has been extensively employed for modeling neurological disorders with a known genetic cause, such as FXS (Fmr1 KO) (FXS)39, Dravet syndrome (DS-Scn1a KO)40, ASD Nrxn1a KO41, Nlgn3 KO42, Phelan-McDermid syndrome (PMDS-Shank 3 KO)43 or RS (Mecp2 KO)44.