Fig. 2.

Targeted resequencing on 39 ODs confirms that many genes are mutated at low frequency. Of the known cancer genes (IDH1/2, TP53, NOTCH1, EGFR, CDKN2A, NF1, PIK3R1 and PTEN), a total of 48 mutations (range 1–4 mutations per tumor) were identified in 39 tumors (known causal cancer genes). Of the genes identified by whole-genome sequencing that thus far are not implicated in oligodendrogliomas, no mutations were found in 39 of the 44 genes in any of the additional 39 tumors (not shown). In the remaining five genes, we identified mutations in only one additional sample (indicated in the figure as low-frequency genes). Distribution of 1p19q status is reported for each identified mutation. Mutations in EGFR, CDKN2A and PTEN were only found in patients with intact 1p19q status