IDH1 and glioma: Notably, mutations at this locus occur in more than 80% of IDH1-M gliomas; as a result, patients with IDH1-M gliomas generally have a better prognosis.21, 22, 23 Su et al.10,14,16,24 found that the mean age of patients with IDH1-M glioma was lower than that of patients with IDH1-W glioma.