Genetic condition that causes tumours along the nervous system

Aetiology

• Mutation in NF1 gene
• Relatively common - 1: 3000 individuals

Clinical features

≳2 of the following is diagnostic:

• ≳6 cafe-au-lait macules
• ≳ neurofibromas of any type, or one plexiform neurofibroma - the neurofibroma is the major NF-1 associated tumour
• Axillary or inguinal freckling
• Optic glioma
• ≳2 Lisch nodules
• Distinctive osseous lesion e.g. sphenoid dysplasia or thinning of long bone cortex, with or without pseudoarthrosis
• First degree relative with NF1

Other clinical features

• Scoliosis
• Can cause learning difficulties
• Phaeochromocytoma (rare)