Neurofibromatosis (NF) is a group of genetic disorders: NF1, NF2 and schwannomatosis (shwon-oh-ma-toe-sis).

NF1 (also known as von Recklinghausen disease) is the most common type, affecting an estimated one in 3000 people in Australia.

NF1 is a variable disorder, which means that it can affect children in many different ways. It usually causes freckles or spots, most often on the skin or eyes, and benign (not cancer) swelling or lumps around the nerves.

Many children with NF1 have no or very few medical problems, but about four in 10 children will have some complications. Treatment for NF1 depends on the particular medical problems your child develops.

NF1 is something you are born with and it is not contagious. Some of the signs of NF1 do not appear until later in life, often around puberty.

Signs and symptoms of NF1

NF1 can affect many different organs in the body in very different ways, but some features of the condition are more common. The major features of NF1 include:

• Café au lait spots: These are flat coffee-coloured patches on the skin. It's common to have one or two of these spots, but people with NF1 always have six or more of these birthmarks, which are always present before the age of five years. The number of café au lait spots is not related to the severity of the disease and they cause no problems or symptoms.
• Freckling: People with NF1 often have freckles in unusual places such as the armpit or the groin. They also tend to appear later (between ages three and five). Skin freckles are smaller than café au lait spots.
  
• Neurofibromas:  These are benign swellings around nerves, which are usually seen as small lumps in or under the skin. Neurofibromas are not normally seen in young children, but tend to increase in number and size around puberty and in adult life. They are usually small and generally cause no physical symptoms.
  
• Lisch nodules:  These are small freckles within the iris (the coloured part of the eye). Lisch nodules develop by puberty in people with NF1. They are usually seen only on examination with a special lamp, and never affect vision or cause other symptoms.

Other common features of NF1 include:

• learning difficulties, which may cause some problems at school
• headaches, which are more common in children with NF1 than in the general population.

Rarely, children with NF1 may have other complications, such as:

• high blood pressure (hypertension)
• curvature of the spine (scoliosis)
• bone problems (seen in the first two years of life)
• large benign nerve tumours (called plexiform neurofibromas – these are usually present at birth)
• spine and brain tumours that are usually benign
• speech delay
• epilepsy.

When to see a doctor

If you are concerned that your child may have NF1, see your GP. You may be referred to a paediatrician or paediatric neurologist (a doctor specialising in childhood disorders of the nerves and brain).

A diagnosis can be made by the doctor following a thorough history and examination. Other tests may be ordered to determine what parts of the body are affected. A blood test can be ordered but is not necessary to make a diagnosis.

Treatment for NF1

There is currently no cure for NF1. Most people with NF1 have no or few medical problems and live normal lives, with no need for treatment. However, because every person with NF1 is at risk of complications from this disorder, it is important that they are regularly reviewed by a doctor who is familiar with the condition. Young children should be seen every six to 12 months, and older children every year. This monitoring will pick up any complications early so that treatment can be started immediately. Different specialists will treat your child, depending on the medical problem that may have developed.

It is very important that children with NF1 have their eyes checked regularly, as they are at risk of developing optic gliomas. Optic gliomas are small tumours on the nerves behind the eyes. The tumours are benign, but can affect vision by putting pressure on the nerves. Optic gliomas can be treated if detected early.

What causes NF1?

About one in two children with NF1 inherit it from a parent with NF1. The other cases are due to a new, spontaneous change that happened for an unknown reason (sporadic change) in the gene for NF. When a child has sporadic NF1, neither of their parents is affected. However, there is a one-in-two chance that the child will pass on the affected gene to their future children.

Because NF is variable, it is possible that the children of a mildly affected parent could be more seriously affected. On the other hand, the children of a severely affected parent who inherit the condition may be less severely affected than the parent who has the disorder.

Key points to remember

• NF1 is a variable disorder, and affects children in many different ways.
• It usually causes freckles or spots, and benign swelling around the nerves.
  
• Many children with NF1 have no or very few medical problems.
• Every child with NF1 is at risk of complications, so it is important to have regular reviews by a doctor and regular eye checks.

For more information

• Children's Tumor Foundation: Understanding NF
• See your paediatrician or paediatric neurologist.

Developed by The Royal Children's Hospital General Medicine and Neurosciences departments. We acknowledge the input of RCH consumers and carers.

Reviewed June 2018.

This information is awaiting routine review. Please always seek the most recent advice from a registered and practising clinician.

Kids Health Info is supported by The Royal Children’s Hospital Foundation. To donate, visit www.rchfoundation.org.au.