Diffuse gliomas can be divided based on presence or absence of mutation in isocitrate dehydrogenase (IDH) genes. IDH-mutant diffuse gliomas represent a wide range of clinical outcome, which is not accounted for by current clinical and pathologic parameters. To address this, we aim to identify and characterize a predictive signature of outcome in diffuse gliomas to better understand this heterogeneity in outcome. A total of 310 IDH mutant glioma samples with methylation data were used for the analysis together with 419 samples from The Cancer Genome Atlas (TCGA), utilizing methylation, mRNA, copy number variation (CNV) and mutation data to identify unique molecular signatures that predict patient outcome. Methylation analysis from our test cohort identified signatures from Cox regression analysis that split the glioma cohort into two prognostic groups that strongly predicted survival (p-value