Multiple animal models of autism demonstrate abnormalities in Ras-MAPK signaling including Rett syndrome (Mellios et al., 2018), BTBR strain (Seese et al., 2014; Cheng et al., 2017), 16p11del (Pucilowska et al., 2015), fragile X syndrome (Soong et al., 2008), neurofibromatosis type 1 (Costa et al., 2002), Noonan syndrome (Lee et al., 2014), Costello syndrome (Schreiber et al., 2017), cardio-cutaneo-facial syndrome (Anastasaki et al., 2009), and SynGAP1 syndrome (Rumbaugh et al., 2006). The gene discussed is SYNGAP1; the disease is atypical Rett syndrome.