NF2 and meningioma: Young patients with NF2 (<33.7 years) had a more severe clinical phenotype compared to older patients with NF2 (>33.7 years) with respect to their vital status (deceased, % = 38 vs. 0), the presence of meningiomas (patients, % = 100 vs. 38), and the total tumor load (tumor count, median = 15 vs. 5).