In a minority of tumors found across all patient subgroups, the pathogenic gene variants in NF2 were accompanied by variants in other genes, such as LZTR1 and SMARCB1, two candidate genes for an alternative diagnosis of 22q-related schwannomatosis (SWN), and tumor suppressor gene TSC1, which may function as a co-factor in tumorigenesis. This evidence concerns the gene LZTR1 and schwannomatosis.