Neurofibromatosis 1 (NF1) is a common, inherited autosomal dominant disease
The birth incidence is between 1 in 2,500 and 1 in 3,000, with about half being the first in their families to be affected.
Diagnostic criteria are that you need two or more of the following:
- 6 or more cafe au lait macules (>0.5 cm in children and 1.5cm in adults)
- 2 or more cutaneous/subcutaneous neurofibromas or 1 plexiform neurofibroma
- axillary or groin freckling
- optic pathway glioma
- 2 or more Lisch nodules
- bony dysplasia (sphenoid wing dysplasia, bowing of long bone +/- pseudarthrosis
- parent or child with NF1
Patients with NF1 are at risk of a number of problems including optic pathway gliomas, CNS tumours, hypertension and congenital heart disease.
Orthopaedic problems include:
- bowing of long bones +/- pseudarthrosis
- scoliosis
- osteoporosis
Oncological problems include:
- benign tumours (neurofibroma, glomus tumours)
- malignant tumours (10% lifetime risk of malignant change in plexiform neurofibromas (to malignant peripheral nerve sheath tumour), optic pathway gliomas, cerebral gliomas, phaeochromocytoma, rhabdomyosarcoma, juvenile myelomonocytic leukaemia, breast cancer in women)
Specialist neurofibromatosis clinics do exist but are few in number.
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