Neurofibromatosis type 1 is a multifaceted autosomal dominant disorder caused by germline mutations in the NF1 tumour suppressor gene. Approximately all people with neurofibromatosis type 1 develop pigmentary lesions and dermal neurofibromas. Some individuals develop skeletal abnormalities (scoliosis, tibial pseudarthrosis and orbital dysplasia), brain tumours (optic pathway gliomas and glioblastoma), peripheral nerve tumours (spinal neurofibromas,...