Neurofibromatosis is a set of three genetic conditions which cause tumours to grow along the nerves. The name “neurofibromatosis”, translated roughly, means “nerve tumour increase”. Tumours are non-cancerous but may cause a range of symptoms of varying severity. Neurofibromatosis can affect all ages, races and genders.
There are three conditions which come under the heading “neurofibromatosis”:
- Neurofibromatosis type 1 (NF1), sometimes known as von Recklinghausen disease
- Neurofibromatosis type 2 (NF2)
In some patients, marks and tumours caused by NF1 may lead to changes to your appearance. This can impact your mental health. NF2 and schwannomatosis can also lead to very noticeable visible differences. On this page, we focus mainly on NF1, as this is the most common form of neurofibromatosis. However, we have also included some information about NF2 and schwannomatosis – you can skip to that section of the page by clicking here.
You can find out more about NF2 and schwannomatosis on the Nerve Tumours UK and NHS websites:
NF1 causes a lot of different symptoms. Some of these may affect patients very mildly, causing little more than minor skin changes. About a third of patients have a related medical condition at some point in their lives. These related conditions may be mild or more severe.
Symptoms of NF1 may include the following, although you won’t necessarily have all of these symptoms:
- Painless coffee-coloured patches (known as “café-au-lait spots”) may be present at birth or develop in the first three years.
- Freckle clusters in unusual places, particularly the armpits or groin, which usually appear by age 5.
- Non-cancerous nerve tumours, known as “neurofibromas”. These may appear as pea-size bumps on the skin (cutaneous neurofibromas). If they develop where several nerves meet (plexiform neurofibromas), large swellings may occur. These can cause pain, weakness, numbness, bleeding and, depending on the location, bowel or bladder problems. The number of tumours varies.
- Tumours of the optic pathway affect around 15% of children with NF1, usually appearing by age 6. Smaller tumours may not affect the vision at all, but faster-growing tumours can interfere with the eyesight.
- Growths on the iris of the eye (known as “Lisch nodules” or “iris hamartomas”), which are usually harmless.
- Bone problems, often affecting the eye socket and tibia (shinbone).
- High blood pressure.
- Symptoms affecting physical development, including scoliosis (which causes the spine to curve sideways), which affects about 10% of NF1 patients. Other symptoms include a larger-than-average head and smaller overall size.
- Around half of children with NF1 have attention deficit hyperactivity disorder (ADHD).
- Between one and two-thirds of people with NF1 have learning difficulties.
Other symptoms which may occur:
- Malignant peripheral nerve sheath tumours – cancers which typically develop in the late 20s or early 30s.
- Brain tumours, which may cause no noticeable symptoms.
- Gastrointestinal symptoms, depending on the location of tumours, which may cause pain, bleeding from the bottom and diarrhoea or constipation.
NF1 may be affected by pregnancy. Most women with NF1 should be able to have a healthy pregnancy. Sometimes, more neurofibromas can appear because of hormonal changes brought on by pregnancy.
Women under 50 who have NF1 are at an increased risk of breast cancer, and should begin screenings aged 40.
How do symptoms affect the appearance?
NF1 may not affect the way you look. However, some people with NF1 experience one or more symptoms which affect their appearance:
- Café-au-lait spots, the most common symptom, may be the only visible symptom of NF1.
- In some patients, neurofibromas may cause significant visible differences. However, in many cases, neurofibromas may be invisible to others.
- Scoliosis (where the vertebrae which make up the backbone form a curve instead of being straight).
- An enlarged head, smaller-than-average size are other possible symptoms which affect the physical appearance of people with NF1.