Extended Data Fig. 1: Data analysis workflow.

Fifty nine tumor samples from 56 NF1-glioma patients with 43 matched normal were profiled with WES, DNA Methylation profiles (31 tumors) and RNA sequencing (29 tumors). WES was used to call NF1 germline mutations using HaplotypeCaller and Somatic-germline log odds filter. Somatic SNVs were called from WES data by integrating the results of five algorithms (Freebayes, MuTect, Strelka, VarDict and VarScan). Recurrent CNVs were detected by GATK and GISTIC2. SNVs and CNVs were validated by Sanger sequencing (93% validation rate) and genomic qPCR (96% validation rate), respectively. Neoantigen prediction was obtained using netMHCpan and HLA genotype was determined by Polysolver, Optitype, Phlat and Seq2hla and validated by affinity binding kinetics. COSMIC cancer mutation signatures were identified by deconstructSig and compared to those occurring in sporadic glioma. DNA Methylation arrays were used to classify NF1 glioma in the methylation subtypes of sporadic glioma form the TCGA pan-glioma dataset (KNN). RNAseq was used to define gene expression clusters and immune subtypes of low-grade NF1-glioma and results were confirmed by RT-qPCR and immunohistochemistry. Integrative analysis of gene expression and DNA Methylation identified epigenetic signatures characterizing immune subtypes of low-grade glioma. A pan-glioma gene regulatory network was used to identify MRs of the ATRX-mutant phenotype in LGm6 sporadic and NF1-glioma (RGBM). Finally, the impact of ATRX mutation on survival was assessed using TCGA pan-glioma and NF1-glioma data.