What is Neurofibromatosis?

Most people have never heard of neurofibromatosis and yet there are more people worldwide affected by the condition than by cystic fibrosis. Both forms of neurofibromatosis (Nf) are complicated genetic conditions, making them difficult to describe in a simple and straightfoward way. This difficulty is made worse because the name 'neurofibromatosis' refers to two separate disorders.

Type one (Nf1)

Neurofibromatosis type one (Nf1) is more common than type two, affecting one in every 2,500 people worldwide. About half inherit it from an affected parent, but the rest develop it spontaneously, shortly after conception.

Diagnosis

A diagnosis of Nf1 is made when there are six or more coffee coloured marks on the skin. This usually happens before the age of two, though sometimes they may not appear until a bit later. Freckling occurs in unusual places, such as under the arms, around the neck or in the groin. Neurofibroma (small lumps and bumps) appear as a child grows older and these can be unsightly if they are on the face or other exposed areas of the body.

Complications

Complications include: specific learning difficulties, behavioural problems, tumours on the nerves around the eye (optic glioma), large non-cancerous tumours on the skin (plexiform neurofibroma), malformation of the long bones (pseudarthrosis) and high blood pressure. Depending on how badly affected an individual is, Nf1 can lead to both disfigurement and disability.

Type two (Nf2)

Neurofibromatosis type two (Nf2) is a rare condition (one in 35,000) but is always more serious than Nf1. Symptoms appear from the late teens onward and the first sign is usually loss of hearing.

Diagnosis

In Nf2 there are fewer outward signs than appear in Nf1 but the tumours, which are almost always non-cancerous, grow on the spinal cord and in the brain. The most serious of these tumours are those on the nerves of balance which, as they grow, affect the nerves that control hearing, often leading to total deafness. Currently, the only treatment is surgical removal and this can lead to facial paralysis and related problems.

The Neurofibromatosis Association

The Neurofibromatosis Association is the only charity in the UK concerned with the welfare of those affected by either condition. For further details visit: www.nfauk.org

• Living with neurofibromatosis