Mutations in MBD1, MBDs 3 to 6, SETDB1, and SETDB2 have been genetically implicated in autism (www.gene.sfari.org), and mutations in MECP2 are responsible for Rett syndrome, a neurodevelopmental disorder that shares features with autism (Chahrour & Zoghbi, 2007). Here, MECP2 is linked to autism.