Increased aneupleudy and/or total CNV load is associated with poorer prognosis and poorer prognostic methylation classes in IDH-mutant astrocytomas.24,73,75,103,104 High mutational burden has been described in recurrent IDHmt astrocytoma in particular following treatment with temozolomide due to defects in mismatch repair genes, which is associated with enhancing recurrences and a worse prognosis and development of discontiguous disease.57,105. This evidence concerns the gene IDH2 and astrocytoma (excluding glioblastoma).