Neurofibromatosis type 1 (NF1), formerly called von Recklinghausen disease, is an autosomal dominant condition caused by a mutation in the NF1 gene located on chromosome 17q11.2 encoding for neurofibromin, a 2818 aminoacids protein which functions as a negative regulator of RAS activity. This evidence concerns the gene NF1 and neurofibromatosis type 1.