Neurofibromatosis is the general name for a number of genetic conditions that cause tumours to grow along your nerves.
Tumours are abnormal tissue growths. In neurofibromatosis, the tumours are usually non-cancerous (benign).
Neurofibromatosis type 1 (NF1) is the most common type, affecting about 1 in 3,000 births. This is covered separately – read about neurofibromatosis type 1.
Neurofibromatosis type 2 (NF2) is a less common type, affecting about 1 in 33,000 people.