NF2 and schwannomatosis: However, instead of constitutional (germline) NF2 mutations, independent somatic mutations affecting both NF2 alleles are frequently found in schwannomas of patients with schwannomatosis (Jacoby et al. 1997; Kaufman et al. 2003; Boyd et al. 2008; Hadfield et al. 2008; Sestini et al. 2008; Hutter et al. 2014; Paganini et al. 2015a; Piotrowski et al. 2014; Smith et al. 2015, 2016).