IDH1 and oligodendroglioma: We found a strong association with IDH mutated tumours at 8q24.21 (rs55705857), in particular with triple-positive glioma [P = 1.27 × 10−37, OR = 9.30 (6.61–13.08)], which corresponds to the WHO 2016 oligodendroglioma classification [Supplementary Fig. 6 (Online Resource 1), Supplementary Table 3 (Online Resource 2)].