Kids Health Info

Neurofibromatosis

  • Neurofibromatosis (NF) is a genetic disorder affecting one in 3000 people. There are two types of Neurofibromatosis, NF1 and NF2. NF1 is much more common than NF2, and is caused by a change in a gene on chromosome 17.

    What is neurofibromatosis 1 (NF1)?

    NF1 is a variable disorder which can affect the skin, eyes and nerves. Many people with NF1 have no or very few medical problems. About four in 10 people with NF1 will have some medical problems related to this disorder.

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

    About one in two people with NF1 inherited it from an affected parent. The other half are due to a spontaneous (new, or 'sporadic') change in the gene for NF in that person. When a person has sporadic NF1, neither of their parents is affected.  However, there is a 50:50 chance that the affected gene will be passed on to each child of that person.

    This pattern of inheritance - where there is a 50% chance that an affected person's child will be affected - is known as 'autosomal dominant' inheritance.

    Because NF is very 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.

    What are the signs for diagnosis?

    NF1 can affect many different organs in the body in very variable ways, but some features of NF1 are more constant and are used for diagnosis. The major features of NF1 include:

    Café au lait spots: These are flat coffee-coloured patches on the skin. Most people 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. People with NF1 often have freckling in unusual places such as the armpit or the groin.

    Neurofibromas:  These are benign swellings around nerves, which are usually seen as small lumps in or under the skin. Neurofibromas are not usually seen in the first few years of life, 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, pigmented 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 ophthalmological equipment (a slit 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.

    It is very important that people 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.  They are benign (not cancerous), but can affect vision by putting pressure on the nerves. These can be treated if detected early and this is why regular eye checks are very important in people with NF1, especially during childhood.

    Other (rare) complications of NF1 include:

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

    Treatment

    Most people with NF1 have no or few medical problems and live normal lives. 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 familiar with the condition. We recommended that small children are seen every six to 12 month, older children every year and adults every one to two years. This monitoring will pick up any complications early so that treatment can be started immediately.

    The gene that causes NF1 has been identified. Much research is being carried out in this area and there is a realistic hope for more effective treatments for the complications of NF1 within the next five to 10 years.

    For more information

     

    Developed by RCH Departments of General Medicine and Neurosciences. First published 2003. Updated November 2010.



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This information is intended to support, not replace, discussion with your doctor or healthcare professionals. The authors of these consumer health information handouts have made a considerable effort to ensure the information is accurate, up to date and easy to understand. The Royal Children's Hospital, Melbourne accepts no responsibility for any inaccuracies, information perceived as misleading, or the success of any treatment regimen detailed in these handouts. Information contained in the handouts is updated regularly and therefore you should always check you are referring to the most recent version of the handout. The onus is on you, the user, to ensure that you have downloaded the most up-to-date version of a consumer health information handout.