Neurofibromatosis type 1 (NF1, MIM #162200) is a common AD neurocutaneous disease, caused by mutations in the NF1 tumor suppressor gene (MIM # *613113), with a prevalence of 1:2000–1:5000 (Rasmussen and Friedman 2000; Evans et al. This evidence concerns the gene NF1 and Alzheimer disease.