The specific position of the mutations correlates with disease severity: splice site mutations located in the first five exons and truncating mutations in exons 2–13 of NF2 gene, causing premature termination of the protein, have been associated with severe phenotypes, while splice site mutations in exons 11–15 and 3’ truncating mutations (exons 14–15) entail decreased tumor incidence and lower mortality [17,20]. This evidence concerns the gene NF2 and neoplasm.