This study will perform a proof of concept study to determine the optimal strategy for comprehensively characterizing somatic genetic events in individual tumors with a focus on grade II pediatric astrocytoma. We anticipate that these studies will determine the important oncogenes and tumor suppressor genes that drive pediatric low-grade glioma development. We also anticipate that an understanding of the molecular pathways disrupted by these mutations will guide the development of rational therapeutics for this disease. If successful, it will enable rapid follow-up with an extended characterization of larger numbers of tumors to identify the recurrent events that cause this disease.