In contrast, the other SMARCB1 tumor predisposition syndrome, schwannomatosis, is typically caused by heterozygous non-truncating germline SMARCB1 mutations that mostly occur in exons 1, 2 or in the 3′-untranslated region (3′UTR)46,47. The gene discussed is SMARCB1; the disease is BAP1-related tumor predisposition syndrome.