Because BRAF V600E mutations have been reported in other low-grade neoplasms such as pilocytic astrocytoma, dysembryroplastic neuroepithelial tumors, and pleomorphic xanthoastrocytoma (discussed below), the presence of a V600E mutation in a low-grade glioma is not diagnostic. The gene discussed is BRAF; the disease is pleomorphic xanthoastrocytoma.