DNA methylation has recently moved to centre stage in the aetiology of human neurodevelopmental syndromes such as the fragile X, ICF and Rett syndromes. These diseases result from the misregulation of genes that occurs with the toss of appropriate epigenetic controls during neuronal development. Recent advances have connected DNA methylation to chromatin-remodeling enzymes, and understanding this link will be central to the design of new therapeutic tools.