Neurofibromatosis

What is neurofibromatosis?

Neurofibromatosis (NF) is a group of neurological and genetic conditions. It causes symptoms that may affect your brain, spinal cord, nerves and skin. Symptoms vary and depend on the neurofibromatosis type but can include birthmarks and the growth of usually noncancerous (benign) tumors. You may inherit this condition from your biological family, but up to 50% of cases happen randomly, without any biological history.

What are the types of neurofibromatosis?

There are three types of neurofibromatosis:

• Neurofibromatosis type 1 (NF1): NF1 is the most common type. It causes café au lait spots, nerve tumors (neurofibromas), armpit and groin freckles, eye nerve tumors and bone deformities (scoliosis).
• NF2-related schwannomatosis, formerly known as neurofibromatosis type 2 (NF2): NF2-related schwannomatosis causes slow-growing nerve tumors, hearing changes, vision changes (cataracts) and numbness or weakness (peripheral neuropathy).
• Schwannomatosis (SWN): SWN is the least common type and it includes several subtypes depending on the specific genetic mutation that causes them (including SMARC-B, LZTR, XXX). Some cases don’t cause symptoms. In others, it causes slow-growing nerve tumors (schwannomas) sometimes located only on one part of your body, chronic pain, numbness and tingling in your fingers and toes.

How common is neurofibromatosis?

Neurofibromatosis type 1 makes up about 96% of all cases of the condition. This equals about 1 in 3,000 births worldwide annually. Neurofibromatosis type 2 affects 3% of all neurofibromatosis cases, which is approximately 1 in 33,000 births worldwide annually. Around 1% of all neurofibromatosis cases are schwannomatosis.

What are the symptoms of neurofibromatosis?

Symptoms of neurofibromatosis vary by type. Some types won’t cause symptoms, while others may cause severe symptoms. The most common symptoms out of all three types include:

• Tumors: Tumors are an abnormal cluster of cells that form a solid mass of tissue. Different types of cells create different types of neurofibromatosis tumors. The tumors grow slowly and aren’t cancerous (benign) but some can turn into cancer. The tumors that grow on your nerves are known as neurofibromas.
• Skin growths: Skin growths can include birthmarks, like café au lait spots or freckles that form in your armpits and groin area. Small, soft, pea-sized bumps can form on your skin — these are called cutaneous neurofibromas.

Other signs and symptoms may include:

• Hearing or vision loss.
• Spine curvature (scoliosis).
• Muscle weakness.
• Numbness or tingling.
• Pain and headaches.
• Behavioral changes like attention-deficit/hyperactivity disorder.
• Learning difficulties.
• Seizures.

What does neurofibromatosis look like?

Neurofibromatosis looks different for each person diagnosed with the condition.

Small, round bumps (about 1 centimeter or the size of a pea) may form on your skin. These are neurofibromas. Some people have more than two of these small bumps or one larger skin growth that forms from multiple nerves under their skin (plexiform neurofibroma).

You might also notice café au lait spots. These are flat, light-to-dark brown birthmarks that range in size and shape. You’ll likely have multiple (six or more) café au lait spots on your skin.

Freckles are common on your face, but not with neurofibromatosis. You’ll likely develop freckles in your armpits and your groin area. Freckles look like small, red-to-brown polka-dots.

At what age does neurofibromatosis appear?

Symptoms of neurofibromatosis can be present at birth, while others develop as you age into an adult. For example, neurofibromas may show up on your baby’s skin when they’re born. In many cases, these usually appear during the teenage years. It’s common for café au lait spots to develop on your child’s skin during their first few years. Groin and armpit freckles can appear between ages 3 and 5. Symptoms of schwannomatosis usually appear during adulthood, around age 30.

What causes neurofibromatosis?

A genetic change (mutation) causes neurofibromatosis. The causes of each type are as follows:

• Neurofibromatosis type 1 (NF1): NF1 is a gene that regulates neurofibromin protein production. This protein suppresses tumors.
• NF2-related schwannomatosis/neurofibromatosis type 2 (NF2): NF2 (merlin) is a gene that regulates another neurofibromin protein. This protein also suppresses tumors.
• Schwannomatosis: The SMARCB or LZTR1 genes can cause schwannomatosis. Many cases have an unknown genetic cause.

When a mutation happens to one of these four genes, your proteins don’t have the instructions needed to regulate cell growth, which causes tumors to form in your body.

You can inherit NF1 or NF2 from your biological parents in an autosomal dominant pattern. This means that you only need one copy of the genetic change from one of your biological parents to develop this condition. Around half of the people diagnosed with NF1 receive a spontaneous genetic mutation that isn’t present in their biological family history. Many people with NF2 also receive a spontaneous genetic mutation, and approximately 85% of schwannomatosis cases happen randomly, without a known genetic cause.

What are the risk factors for neurofibromatosis?

Neurofibromatosis can affect anyone. You’re more likely to develop a type of neurofibromatosis if it runs in your biological family.

What are the complications of neurofibromatosis?

Complications of neurofibromatosis may include:

• Hearing loss.
• Vision loss.
• Chronic pain.
• Learning and behavioral problems.
• Cardiovascular conditions (hypertension, congenital heart conditions).
• Problems with self-esteem due to skin symptoms.
• Higher risk of cancers compared to the general population, including breast cancer, and sarcoma (soft tissue cancer).

While less common, some neurofibromatosis tumors can develop into cancer.

How is neurofibromatosis diagnosed?

A healthcare provider will diagnose neurofibromatosis after a physical exam and testing. Your provider will examine your skin to look for symptoms like café au lait spots or neurofibromas. They’ll also look for scoliosis and test your blood pressure, vision and hearing. They’ll learn more about your health and family medical history during this exam, so let your healthcare provider know if you’re aware of any biological family members who have neurofibromatosis.

Diagnostic criteria for each type vary and most commonly, the diagnosis can be made by clinical examination, but certain tests can help your provider narrow down the cause of your symptoms. Imaging tests, like an MRI, X-ray or CT scan can help your provider see how the condition affects your nervous system. Genetic testing can also determine the genetic variant that caused your symptoms, but providers don’t know of every gene that causes this condition.

A diagnosis can happen several years after you first have symptoms. Some people don’t receive a diagnosis until they’re adults. That’s because neurofibromatosis symptoms appear in stages over time.

How is neurofibromatosis treated?

It’s very important that your neurofibromatosis care is under the direction of a multidisciplinary team with experience caring for individuals with NF. Your treatment team includes:

• Neuro-oncologists.
• Neurosurgeons.
• ENT surgeons.
• Plastic surgeons.
• Psychotherapists.
• Audiologist.
• Genetic counselors.

While there isn’t currently a cure for neurofibromatosis, there are multiple advances in diagnosing and treating NF-related tumors and your healthcare provider can direct you toward the best treatment available for your condition.

No treatment is necessary if you don’t have symptoms or your symptoms don’t interfere with your daily life. Your provider will recommend annual or twice-annual checkups to monitor the progress of the condition.

Your healthcare provider might recommend the following treatment:

• Tumor removal: Surgery can remove tumors from your skin and other parts of your body.
• Medications: The U.S. Food and Drug Administration (FDA) approved selumetinib, a medication to stop the growth of tumor cells for children between the ages of 2 and 18 years who are diagnosed with neurofibromatosis type 1-related plexiform neurofibroma not amenable to surgery or if the tumor is causing disability or disfigurement.
• Surgery to repair bone growth abnormalities: If you have scoliosis or other bone growth abnormalities, a healthcare provider may recommend a brace or surgery for severe situations.
• Chemotherapy: This treatment is available for tumors that turn into cancer (malignant tumors). Chemotherapy destroys cancer cells.
• Radiation therapy: Radiation therapy can manage tumor growth for cancers like breast cancer, soft tissue cancer called sarcoma or malignant peripheral nerve sheath tumors (MPNST) or glioma (tumor of the brain).

If neurofibromatosis affects your hearing or vision, your provider may recommend assistive devices like hearing aids or corrective lenses.

Are there side effects of the treatment?

Each type of treatment comes with possible side effects. Your healthcare provider will discuss side effects with you before you begin treatment.

Possible side effects of surgery include:

• Bleeding.
• Infection.
• Neurofibromas returning after removal.
• Nerve damage.

Side effects of chemotherapy include:

• Fatigue.
• Diarrhea or constipation.
• Hair loss.
• Loss of appetite.
• Nausea and vomiting.

Can neurofibromatosis be prevented?

There’s no known way to prevent neurofibromatosis. If you plan on starting a family, talk to a healthcare provider about genetic counseling to learn more about the risks of having a child with a genetic condition.

What is the life expectancy of someone with neurofibromatosis?

Neurofibromatosis doesn’t usually affect your life expectancy. The location of the tumors can make certain aspects of your daily routine difficult without assistance, like hearing and seeing, for example. Complications can lead to possible life-threatening outcomes, like cancer, if left untreated.

When should I see a healthcare provider?

Visit a healthcare provider if you notice symptoms of neurofibromatosis on your or your child’s skin, like:

• Six or more café au lait spots.
• Bumps on your skin without a known cause.
• Freckles in your armpits or groin.

Other symptoms that indicate you should see a provider include:

• Changes to your hearing and/or vision.
• Pain without a known cause.
• Muscle weakness.
• Numbness or tingling in your hands and toes.

If you have neurofibromatosis, your provider will schedule regular checkups to monitor your symptoms, usually at six- to 12-month intervals. Schedule an additional appointment if you notice any new or worsening symptoms.

What questions should I ask my healthcare provider?

• What’s causing my symptoms?
• What’s the risk that my future children will inherit this condition?
• What type of treatment do you recommend?
• Are there side effects of the treatment?
• How often should I schedule follow-up appointments?
• Are there any clinical trials available for me?
• Do I need to see a fertility specialist?