Neurofibromatosis type 1 (NF1; MIM 162200) is an autosomal dominant disease characterised by café-au-lait spots, axillary/inguinal freckling, iris hamartomas, neurofibromas, optic nerve gliomas, and skeletal abnormalities including sphenoid dysplasia, caused by mutations in the NF1 gene [116, 117]. The gene discussed is NF1; the disease is plexiform neurofibroma.