Neurofibromatosis type 1 (NF1) is a relatively common inherited condition affecting approximately one in 3000 people. It is caused by a change in the NF1 gene on chromosome 17. It is also known as von Recklinghausen’s disease, named after the doctor who first described it in the 19th century.
NF1 is characterised by a number of different features that commonly occur together. These include:
- Café au lait spots — these are light coffee-coloured patches of skin found anywhere on the body, becoming obvious during the first 2 years of life. One or 2 of these lesions is common in the general population, but people with NF1 usually have at least 6 of these which are always present before the age of 5 years.
- Freckles — occurring in areas not usually exposed to the sun, such as the armpits and the groin. They usually appear in the first 5 years of life.
- Neurofibromas — growths on the nerves that can occur anywhere on the body, but are most visible in the skin. Generally these are harmless, although depending on their location, they may cause concern from a cosmetic viewpoint. They tend to increase in number with age.
- Lisch nodules — these are small pigmented freckles seen in the coloured area of the eye (the iris). They do not affect vision.
The majority of people with NF1 will not have serious medical or physical complications. The course of the disease varies widely among individuals. At present there is no way of predicting who will develop complications of their NF1 or how severely they will be affected by these complications.
The most common complications of the disease are related to the cosmetic appearance of NF1 and learning difficulties. More serious complications of NF1 include:
- Plexiform neurofibromas — larger growths developing on nerves. These can cause problems not only because of their size and appearance, but they also have the potential to turn malignant (cancerous), although this isn’t common.
- Learning problems — children with NF1 often have academic difficulties. They may also have problems with organisational skills, impulsivity, speech and muscle coordination.
- Optic gliomas — benign (non-cancerous) tumours of the visual pathway. These may need treatment if they grow in size, or cause significant symptoms.
- Scoliosis — curvature of the spine.
NF1 is a progressive disease; that is, it tends to get worse with age. There is no cure for NF1. It’s important for people with NF1 to regularly see their doctor, so that any complications of the disease can be picked up early and the symptoms of these complications can be treated.
If you are diagnosed with NF1, it is important that all of your immediate (first-degree) relatives are checked for the disease. About half of the people in Australia with NF1 will have inherited it, and the other half will have been born with the faulty gene that occurred spontaneously.
Regardless of the origin of the disease, a person with NF1 has a 50 per cent chance of passing it on to their child. All people with NF1 are encouraged to undergo genetic counselling before conceiving a child.