Abstract

Neurological disorders caused by mutations in a single gene offer us the prospect of understanding at a molecular level the chain of events leading to pathology. In turn, these specific examples may hold lessons that apply to to autism spectrum disorders more broadly. Rett syndrome, for example, is a profound disorder that almost exclusively results from mutations in the X-linked MECP2 gene. Duplication of the MECP2 gene leads to a distinct but equally serious disorder. A bottom-up approach to therapy requires knowledge of the molecular functions normally associated with MeCP2. It is known that the protein binds to sites on DNA that are chemically altered by DNA methylation and there is evidence that it interprets this “epigenetic” mark. Both the spectrum of mutations causing Rett syndrome and biochemical and genetic analyses of MeCP2 function support the view that its primary role is to restrain transcription of many genes in a DNA methylation-dependent manner via recruitment of co-repressor complexes. Alternative hypotheses for MeCP2 function have been put forward, and it is therefore necessary to rigorously test the key theoretical predictions of each. My talk will present the results of experiments of this kind, which suggest a global role for MeCP2 in restraining transcription in the brain. Taken together with earlier demonstrations that the Rett-like phenotype is potentially curable, this new knowledge may facilitate future approaches to therapy.