Rett syndrome begins to appear in affected females at the age of 6 to 25 months. They begin loosing voluntary control of hand movements and their communication skills deteriorate. Rett syndrome has been shown to be associated with mutations in the MECP2 gene, which is known to encode a protein called the Methyl-CpG-Binding Protein 2 (MeCP2).

Evidence has suggested that the loss of MeCP2 protein during a critical period in the early months of life leads to Rett syndrome. Research reported this month in Science (“Adult neural function requires MeCP2” published July 8, 2011) shows that normal adults may express Rett syndrome like symptoms if the MeCP2 protein is no longer expressed.

The report is significant for our understanding of the genetic influence of brain function leading to Rett syndrome since it points to a role of the MeCP2 protein in the ongoing maintenance of normal brain function rather than a transient influence during an early critical period. Both the infant and mature brain depend on the MeCP2 protein to function normally. Just what the mechanism (or mechanisms) of the ongoing influence is, is the critical next step in understanding and treating this disease.