FXYD1 and Rett syndrome: Physical association of these genes with MeCP2 was confirmed by chromatin immunoprecipitation (ChIP) assays that documented MeCP2 binding to promoter regions of Fxyd1, Reln, and Gtl2. This study reports, for the first time, cerebellar expression profiles in Mecp2-mutants and proposes novel MeCP2 target genes that may contribute to the pathophysiology observed in RTT individuals and MeCP2-deficient mice.