Neurofibromatosis type 1

Neurofibromatosis is the name for a number of genetic conditions that cause tumours to grow along your nerves.

Tumours are swellings formed by a growth of cells. In neurofibromatosis, the tumours are usually non-cancerous (benign).

Types of neurofibromatosis

There are two main types of neurofibromatosis:

• Neurofibromatosis type 1 (NF1) is the most common type of neurofibromatosis, affecting about one in 3,000 births.
• Neurofibromatosis type 2 (NF2) is a less common type of neurofibromatosis, affecting about one in 35,000 births.

Despite sharing the same name, these two types of neurofibromatosis are separate conditions with different symptoms and caused by changes in different genes.

This information is about neurofibromatosis type 1 (NF1).

Find out more about neurofibromatosis type 2.

How it affects you

NF1 is a condition you are born with, although some symptoms develop gradually over many years. The severity of the condition can vary considerably from person to person.

In most cases of NF1 the skin is affected, causing symptoms such as:

• pale, coffee-coloured patches with smooth outlines (café au lait spots)
• soft, non-cancerous bumps on or under the skin (neurofibromas)

About one in three people with NF1 also develop a range of further health problems, including:

• high blood pressure
• a curved spine (scoliosis)
• learning difficulties and behavioural problems
• a type of cancer known as malignant peripheral nerve sheath tumours, which affects around 10% of people with NF1 over their lifetime

Read more about the symptoms of neurofibromatosis type 1 and the complications of neurofibromatosis type 1.

Why it happens

NF1 is caused by a genetic mutation. This is where the instructions that are carried in all living cells become scrambled in some way. As a result, the growth of nerve tissue is not controlled properly.

In half of all cases of NF1, the genetic mutation is passed from a parent to their child. In other cases, the genetic mutation appears to develop on its own. This is known as a sporadic mutation.

Although there are genetic tests that can be carried out during pregnancy to check if your child will have NF1, most cases are diagnosed after birth from the characteristic symptoms.

Read more about the causes of neurofibromatosis type 1 and diagnosing neurofibromatosis type 1.

How it's treated

There is currently no cure for NF1. Instead, people with the condition are regularly monitored for further problems and treated if and when these develop.

This can involve surgery to remove tumours and improve bone abnormalities, medication to control secondary conditions such as high blood pressure, and therapy for behavioural problems.

In many cases, careful monitoring and treatment can help people with NF1 live a full life. However, there is a risk of developing serious problems such as strokes and some types of cancer, which can reduce life expectancy in some people by up to 15 years.

Read more about treating neurofibromatosis type 1.