IDH1 and astrocytoma (excluding glioblastoma): The role of 1p/19q and IDH add yet another layer of complexity with respect to patient outcome as patients with primarily IDH1R132MUT with 1p/19q co-deletion have been shown to have a more favorable prognosis in low grade gliomas (oligodendrogliomas) with a median survival of 8 years compared to IDH1R132MUT with no 1p/19q co-deletion (astrocytoma) which had a median survival of 6.4 years (45).