Due to the strong association of brain glioma with Ollier’s disease, it is justified to offer a treatment with vorasidenib to a patient with a diagnosis of OD IDH R132H mutant, with or without cured AML IDH 132H mutant and with neuroradiological findings suggestive of diffuse low-grade glioma but who refused biopsy of the cerebral lesion? This evidence concerns the gene IDH1 and brain glioma.