MECP2 and autism: RTT affects young girls between 8 and 16 months of age and is characterized by decelerated brain growth accompanied by loss of motor abilities, ataxia, loss of cognitive capability, respiratory dysfunction and autistic features; this regressive course is comparable to that observed in autism and both diseases show dendritic and synaptic abnormalities (Figure 5), suggesting that MeCp2 aberration might be involved also in autism (Shepherd and Katz, 2011).