Type 1 neurofibromatosis (NF1; OMIM 162200) is an autosomal and dominantly inherited cancer predisposition syndrome, caused by constitutional mutations in the NF1 gene encoding the protein neurofibromin (Gutmann et al., 2017; Jouhilahti, Peltonen, Heape, & Peltonen, 2011; Uusitalo et al., 2016). This evidence concerns the gene NF1 and neurofibromatosis type 1.