POLR2A and obstructive hydrocephalus: Gait ataxia and other signs or symptoms attributable to hydrocephalus may help in the diagnostic workup aiming to detect patients with ependymoma‐associated POLR2A variants since obstructive hydrocephalus is present in up to 90% of patients with posterior fossa tumors at diagnosis (Bhatia et al., 2009; Raimondi & Tomita, 1981).