What is neurofibromatosis?Neurofibromatosis (NF) is one of the most common genetic conditions. There are several different types: about one in 2500 people have neurofibromatosis type 1 (NF1). This causes many benign nerve tumours, which can occur anywhere in the body. They first appear during childhood as coffee-coloured spots on the skin. Later in life, more nerve tumours appear as lumps under the skin. NF1 sometimes causes mild learning difficulties. Symptoms of NF1 vary a lot, even between affected people in the same family.
What causes neurofibromatosis?
The cells that make up our bodies grow and multiply in a carefully controlled way. Nerve tumours appear in people with NF1 because some of their nerve cells start to grow unchecked. In 1990, researchers discovered that people with NF1 have an altered version of a gene that usually helps to keep cell growth under control. A genetic test may be able to detect this altered gene before symptoms appear, usually during the first year of life.
How is neurofibromatosis inherited?
About half the people with NF1 are born to unaffected parents, following a genetic change in the egg or sperm. People with NF1 may pass the condition on to their children. With one affected parent, each child has a one-in-two chance of being born with NF1, and a one-in-two chance of being unaffected. Those born with NF1 may pass the condition on to their own children, while those unaffected will not.