Female cells undergo a naturally occurring mechanism to allow for dosage compensation, called X- chromosome Inactivation (XCI) so that X-linked genes are equally expressed in males. In this event, one of the two X chromosomes is randomly silenced due to XCI, which becomes transcriptionally inert. De novo variants in MECP2, a gene on the long arm of the X-chromosome, gives rise to Rett Syndrome (RTT) via a quasi-haploinsufficiency. RTT is a rare and progressive neurodevelopmental disorder that occurs predominantly in females. Disease causing mutations cause either partial or complete loss of function of the protein, MeCP2. MeCP2 acts as a transcriptional regulator and is essential for neurodevelopment. Lack of functional MeCP2 results in unregulated transcription of downstream genes, which can cause a regression in development around 6 months of age, with a hallmark of seizures and other motor defects. Due to random XCI, females that are affected by RTT form a mosaic of cells expressing mutant and wild type alleles. Interestingly, ~15% of human X-linked genes naturally escape XCI. With this knowledge, the Fink lab is utilizing the CRISPR/dCas9 system to synthetically alter the epigenetic state of target genes to resemble those that naturally escape XCI. Our approach is to reactivate the healthy allele that is silenced due to XCI, as an epigenetic therapy for Rett syndrome. CRISPR/dCas9 is a known, site-specific DNA binding tool that can be paired with different effector domains to directly or indirectly drive gene expression. Utilizing the gene specific binding capabilities of dCas9 and pairing it with known effector domains, targeted epigenetic modifications can be made to transcriptionally inactive genes, such as XCI-silenced MECP2. Accomplishing this would drive wild-type gene expression, which would ultimately create more functional MeCP2 protein and allowing for a potential phenotypic rescue.