IDH1 and oligodendroglioma: All 44 oligodendrogliomas with TERT promoter and IDH1/2 mutations also had the 1p/19q allelic deletions and all but 3 of the 47 tumors with 1p/19q allelic losses also contained both TERT promoter and IDH1/2 mutations, indicating that IDH1/2 and TERT promoter mutational analysis may be a comparable prognostic markers to 1p and 19q in oligodendrogliomas (Fisher exact p<0.0001).