Neurofibromatosis type 1
Neurofibromatosis type 1 (NF1) affects mainly skin and nerves. Individuals with NF1 have darker coloured spots (birthmarks) on the skin. They develop noncancerous tumours along the nerves of the skin, and other regions of the body. Some children are born with a growing tumour on a long region of a nerve with a potential to cause symptoms by pressure on organs or nerves (plexiform). It is possible that such a tumour will develop into cancer in adolescence as an adult. Sometimes tumours develop in young children on the nerve from the eye to the brain leading to blindness. Individuals with NF1 have an increased risk for a number of other rare tumours. Females with NF1 between 30 and 50 years have a higher chance of developing breast cancer. NF1 affected people also have an increased risk of high blood pressure and skeletal problems such as a high curvature of the spine. Many children have some form of learning disability, concentration or communication problem.
NF1 is caused by a genetic error in one of the two copies of the NF1 gene on chromosome 17.
The condition is inherited from parent to offspring with a chance of 1 in 2. Half of the individuals with NF1 do not have an affected parent and the genetic error started with the person. This genetic error can be detected by a genetic analysis of the blood to be sure that the patient does not have another condition with spots on the skin.
Children have to be monitored on a yearly basis for vision, blood pressure, growth of plexiform neurofibromas, development, skeletal problems and school career. Depending on the presence or absence of tumours as assessed by a whole body MRI at the age of 16-18 years, adults might need a specific yearly follow-up. Otherwise a follow-up every 3 years might be sufficient. It is recommended that females have yearly mammograms starting at the age of 40 years.
Endorsed by ERN GENTURIS*
* ERN GENTURIS uses AGREE II as a tool for the endorsement of guidelines. The quality of the guideline is evaluated through assessing the rigor and transparency of the guideline development process. The content of the guideline is not evaluated, although selection of the guideline for endorsement includes expert opinion on the usefulness of the content of the guideline.