MECP2 and atypical Rett syndrome: For instance, MeCP2 is a ubiquitous protein that acts as a global repressor of transcription and was found to be involved in Rett syndrome (RTT)20,21, either elimination or overexpression MeCP2 leads to a decrease in the complexity of dendritic arbors22; MeCP2 also strongly inhibits dendritic and spine growth, which depends on the interaction of MeCP2 and DiGeorge syndrome critical region 8 (DGCR8)23.