FOXG1 and Feingold syndrome: Similarly, postnatal restoration of correct gene expression levels has been shown to be beneficial in mouse models of other neurodevelopmental disorders, such as MECP2 Duplication Syndrome [9], Angelman syndrome [10–12], and Phelan-McDermid Syndrome [13], raising the question whether a similar opportunity exists for modification of symptoms of FS with postnatal expression of FOXG1.