This ‘pathway’ approach investigates the Ras/MAPK signaling role in autism traits.  A large sample representing genetic disorders (RASopathies) caused by mutations activating this pathway was compared with sibling controls and autism spectrum disorder (ASD) subjects.  Each RASopathy (Neurofibromatosis type 1, Noonan syndrome, Costello syndrome, and cardio-facio-cutaneous syndrome) is associated with autism traits, with distinct distributions.  Impairment across ASD domains and male autism bias in RASopathy subjects suggest similarities to ASDs.  Individuals with RASopathies should be offered testing and treatment for social communication impairment. Future studies could explore modifying factors contributing to variation within RASopathies and Ras/MAPK signaling in non-RASopathy ASDs. (By Brigid Adviento, http://jmg.bmj.com/content/early/2013/10/07/jmedgenet-2013-101951 )