A special group of genes, known as imprinted genes, on the X chromosome may be an important contributing factor to autism spectrum disorder (ASD). Genomic imprinting is a form of epigenetic gene regulation that leads to one of the two parental copies of a gene being inherited in a transcriptionally silent state. Imprinted genes have only recently been discovered on the X chromosome, and it is important to gain an understanding of the role these genes play in brain development and how they are regulated. The primary goal of this project is to fully characterize the epigenetic regulatory factors that influence transcription of these genes on the X chromosome. Experiments will assess the effect of DNA methylation and activation on gene expression, as well as other regulatory factors. Finally, knockout mouse models targeting genes encoding for regulatory elements will be developed.