NF1 and neurofibromatosis type 1: In addition to providing a strategy for the clinical use of new gene variants, NF1 (MIM*613113) is a model gene for the high rate of new alleles (about 50% of the total burden of mutations [6]) and for their fully penetrant mendelian behavior, which makes them detectable in specific phenotypes belonging to neurofibromatosis type I (NF1) (MIM#162200) (various combinations of multiple café-au-lait spots, axillary and inguinal freckling, multiple neurofibromas, and iris Lisch nodules) [7].