What is Neurofibromatosis?

Neurofibromatosis is a rare condition that causes non-cancerous tumours to grow within the body. There are an estimated 25,000 people in the UK affected by the most common type, known as NF1.

What is neurofibromatosis?

When a person has neurofibromatosis, benign (non-cancerous) tumours can develop within their body around their nervous system. These tumours can cause various issues as well as secondary health problems.

There are two types of neurofibromatosis and both are caused by a faulty gene. Although this gene can pass from parent to child, in around half of cases the faulty gene occurs spontaneously in a family that has no history of the disease.

What are the types of neurofibromatosis?

There are two main types of neurofibromatosis:

• Neurofibromatosis type 1 (NF1).
• Neurofibromatosis type 2 (NF2).

Neurofibromatosis type 1 is more common than type 2 and although the conditions share commonalities, they have different symptoms and causes.

NF1 is a condition that people have from birth, although symptoms are not always obvious immediately. This type of neurofibromatosis usually affects the skin.

Almost all sufferers of neurofibromatosis type 2 develop tumours in their nerves that relate to hearing and balance. The brain and spinal cord can also be affected. The average age of onset for NF2 is around 18-24 years old.

An estimated 1 in 3 people with NF2 develop a milder form of the disease called mosaic NF2. In this instance, symptoms are usually concentrated in one area, which means that only one part or one side of the body is affected.

What are the signs and symptoms of neurofibromatosis?

It is most common for NF1 to affect a person’s skin.

This can result in:

• Birthmarks – these are brown marks that can be placed anywhere on the body, sometimes called ‘café au lait spots’.
• Neurofibromas – soft, benign (non-cancerous) tumours either on or just beneath the skin.
• Freckles – these occur in clusters in places such as the groin, armpits or beneath the breasts.
• Plexiform neurofibromas – this happens when tumours develop in places where multiple nerve branches converge and this causes swelling. They can occur on the skin or deeper within the body causing pain, swelling, bleeding, numbness, weakness and problems with the bladder and bowels such as urinary tract infections (UTIs) or constipation.

Some of the issues experienced by young people with NF1 include:

• Learning difficulties – some children with NF1 develop learning and behavioural problems, although the correlation is not fully understood. This can include attention deficit hyperactivity disorder (ADHD) and a lower than average intellect. It has also been linked to autism spectrum disorder (ASD).
• Eye problems – approximately 15% of children with NF1 grow tumours on their optic pathway at the back of their eye. Children under 7 are at the highest risk of developing this type of tumour. It can result in blurred and reduced vision and is commonly diagnosed with an eye test. Tiny raised bumps within the iris can also develop as a result of NF1. These are called Lisch nodules and do not usually obstruct vision or cause significant issues.

Other signs associated with NF1 include high blood pressure, migraines and occasionally epilepsy.

The signs and symptoms of neurofibromatosis type 2 include:

• Ear/hearing problems – most people with NF2 will get non-cancerous tumours in the nerves that the brain uses to communicate hearing and balance. This can cause problems such as hearing loss, dizziness/balance problems and tinnitus (a constant ringing/buzzing sound in the ear). As the tumours grow, additional problems can occur such as numbness/pain in the face, difficulty swallowing and speech problems.
• Vision issues – around two-thirds of people with NF2 get cataracts. These are cloudy patches in the lens of the eye that make vision blurry. Surgery is sometimes required to correct the lens of the affected eye.
• Skin problems – more than 50% of people with neurofibromatosis type 2 develop tumours on or beneath the skin called schwannomas. They can grow quite large and may be painful if they interact with nerves.
• Peripheral neuropathy – this affects the nerves in a person’s extremities and can result in numbness, burning sensation and muscle weakness in the affected area.
• Brain tumours – one in two people with NF2 develop non-cancerous brain tumours called meningiomas. These can cause a range of symptoms including headaches, nausea, seizures as well as changes in personality, memory and speech.
• Spinal cord problems – it is common for sufferers of neurofibromatosis type 2 to grow tumours along the spinal cord which can cause back pain, muscle weakness and possible mobility problems.

What causes neurofibromatosis?

Both neurofibromatosis type 1 and neurofibromatosis type 2 are caused by a faulty gene. If the NF1 or NF2 gene is faulty, neurofibroma will grow uncontrollably within the nervous system. Neurofibroma are benign (non-cancerous) tumours that grow along a person’s nerve cells.

In 50% of all cases of NF1 the faulty gene has been passed from a parent to their child. Only one parent needs to be a carrier of the gene for the risk to be present. This means that if either of the parents has the faulty gene there is a 1 in 2 chance of their child developing NF2.

In the other 50% of cases the gene seems to develop spontaneously and scientists are unsure why this happens.

It is far more likely that if you have neurofibromatosis, you will have type 1. NF2 is rare, with an estimated 1 in 33,000 people having the condition worldwide according to the National Organisation for Rare Disorders (NORD).

What are the risks of neurofibromatosis?

As the gene can be passed from parent to child there is a risk of a child inheriting the condition if either of their parents carries it. Neurofibromatosis is thought to affect men and women equally.

Becoming pregnant when you have neurofibromatosis is possible and there are a number of routes available that can limit the chance of the gene passing on. However, hormonal changes associated with pregnancy can increase the risk of tumours developing, so careful monitoring is vital.

Women with NF1 who are under 50 years old have an increased risk of developing breast cancer and are recommended to attend regular breast screening appointments from the age of 40.

Vision problems, high blood pressure and headaches are also common in sufferers of NF1. Children with the condition may suffer learning delays and other developmental problems, including:

• Scoliosis (curved spine).
• Larger than average sized head.
• Lower weight and smaller size than average for age.

There is also an increased risk of certain tumours in people with the condition, including a malignant peripheral nerve sheath tumour, which is a type of cancer and gastrointestinal tumour which can cause bleeding, pain and a change in bowel habits and requires specialist care.

People with NF2 are highly likely to develop hearing issues, with many eventually suffering complete hearing loss. As the condition also affects the brain and spinal cord areas, it is not uncommon for serious mobility problems to occur.

Can neurofibromatosis be prevented?

At present no medication or procedures exist that can prevent neurofibromatosis from happening. However, as the condition can be passed from parent to child, if you know that you are a carrier of the faulty gene you may want to speak to your doctor before deciding to have a baby.

You will most likely be referred to a specialist, known as a ‘genetic counsellor’ who can discuss what options are available for those with a family history of NF1 or NF2 who would like to start a family.

These may include:

• Using donor egg or sperm.
• Adoption/fostering.
• Testing during pregnancy (either chorionic villus sampling or amniocentesis).
• A procedure where the eggs are fertilised in a lab setting and only those that test negative for neurofibromatosis are implanted into the womb.

Living with neurofibromatosis

With consistent monitoring and treatment, it is possible for sufferers of NF1 to live a reasonably normal life. Having the condition does come with the risk of developing certain forms of cancer that can lead to a reduced life expectancy.

Those with NF2 are likely to develop significant hearing loss over time and many lose their hearing completely. Symptoms also tend to get increasingly worse, although the speed at which people’s health deteriorates varies from patient to patient.

Tumours that develop within the brain and spinal cord in people with NF2 place significant strain on the body and this can decrease life expectancy.

To make life easier, those with NF2 may benefit from interventions and aids that help them to live with hearing and mobility problems they develop as a result of having the condition, such as:

• Hearing aids.
• Cochlear implants.
• Wheelchair.
• Walking aids (sticks, walking frames etc).

People with NF2 may also benefit from learning to lip-read as their hearing is most likely going to deteriorate significantly over time.

How is neurofibromatosis diagnosed?

NF1 is usually diagnosed in adolescents and adults who present with the typical symptoms that are associated with the condition. Scans and further tests will usually be recommended, followed by a biopsy to check the status of the tumours.

Neurofibromatosis is a condition that requires careful monitoring and treatment, therefore it is important that it is detected as soon as possible so that a treatment plan can be put in place.

NF2 is still rare and usually requires the care of specialists who are trained in this specific disease. If it is suspected that a person has NF2, scans or blood tests may be done to check for signs of the condition.

You might also require assessments to check for complications that commonly arise as a result of NF2 such as tests to assess your sight or hearing.

It is often easier to diagnose neurofibromatosis in adolescents or adults who present with typical symptoms, rather than in children or babies, as it is a condition that gets worse over time. Children may be offered a blood test to check for the faulty NF2 gene, although this test is not 100% reliable.

How is neurofibromatosis treated?

There is no cure for NF1 or NF2 at the moment. Treatment for both includes regular monitoring and treatment for any issues that happen as a result of having neurofibromatosis.

Treatment options for neurofibromatosis type 1 can include:

• Surgery – to treat the tumours or help with bone problems.
• Medicine – this can help with secondary conditions caused by neurofibromatosis, for example high blood pressure.
• Pain management.
• Counselling – many sufferers need psychological support due to having to live with a long-term genetic disorder.
• Physiotherapy.

NF2 is a rare condition that requires specialist care in one of four treatment centres that are located around England. Healthcare experts who understand the condition work in these centres and they are able to create a treatment plan for those who have been diagnosed with neurofibromatosis type 2.

Monitoring for neurofibromatosis type 2 can consist of the following:

• MRI scans – these scans check for any new tumours that might have grown and whether existing tumours are getting bigger.
• Eye tests – these tests check for cloudy patches in the eye called cataracts that cause vision problems.
• Hearing tests – regular hearing checks should pick up on any hearing loss or changes to a patient’s hearing.

These tests will be conducted at least once a year but may be done more often depending on the needs of the patient.

Treatment options for neurofibromatosis type 2 can include:

• Surgery – this comes with its own risks for patients, such as paralysis if tumours are located close to the spinal cord or nerve tissues. Some tumours grow so large that they can damage organs, such as the brain, meaning that surgery becomes necessary even with the risks in mind.
• Radiotherapy – a treatment called gamma knife which uses a highly concentrated beam of gamma radiation to shrink tumours can be used for smaller tumours. This treatment poses a risk of new tumours becoming cancerous – experts consider the risks to be small but they need to be taken into consideration when exploring treatment options.

There are also treatment options for the hearing loss that comes with having NF2, such as:

• Cochlear implants.
• Auditory brainstem implants.

These hearing devices consist of both an internal and external portion. The external portion is able to pick up and process sounds; it then passes them electronically to the internal portion to be received either by the cochlear (part of the inner ear) or the brainstem.

You may also need to have treatment for other problems caused by your neurofibromatosis, such as:

• Cataract surgery (lens replacement in the eye to improve vision).
• Medicine for peripheral neuropathy (a type of nerve damage).
• Therapy for tinnitus (a constant ringing or buzzing in the ears).

Neurofibromatosis is a rare genetic disorder that is characterised by tumours developing throughout the body’s nervous system. There are various risks associated with the two main types of the condition (NF1 and NF2), including an increased risk of certain cancers or benign tumours growing to the point that they affect the body’s organs and cause problems. Neurofibromatosis, therefore, requires careful monitoring and a specialist treatment plan in order for those affected by it to live as full a life as possible.