NF1 and central nervous system cancer: However, the available literature manages to detail significant predictive factors for poor prognosis of visual pathway gliomas, such as an early age of onset, i.e., between 1 and 3 years; site of origin (postchiasmatic—behind the junction); and the presence of hypothalamic symptoms—along with increased intracranial pressure, partial resection and the absence of mutations in NF1.