Neurofibromatosis type 1 & type 2 (NF1 & NF2)

Neurofibromatosis type 1 and neurofibromatosis type 2 are rare genetic disorders that affect the nervous system. There are no known causes or cures, and neither condition is infectious.

Although there are similarities, each condition has important differences from the other. Your Advocate Health Care doctor can connect you with a team of specialists to manage your neurofibromatosis symptoms and treatments.

Understanding neurofibromatosis type 1 and neurofibromatosis type 2

It all starts at the genetic level. Both neurofibromatosis type 1 (NF1) and neurofibromatosis type 2 (NF2) have symptoms that arise from genetic mutations. These mutations allow defective proteins to be produced during cell growth leading to disruption of messages from the brain to the muscles.

There are two types of genetic mutations:

• Inherited genetic mutations are inherited from parents.
• Sporadic genetic mutations happen randomly either before or after birth.

Both inherited and sporadic genetic mutations lead to the symptoms of NF1 and NF2. That’s where things start to diverge.

Symptoms of neurofibromatosis type 1 (NF1)

NF1 is much more common than NF2. Its symptoms can usually be noticed at birth or in the first couple of years of life. Symptoms include:

• Neurofibromas – small, soft tumors on or under the skin that grow on nerves. Some may be present at birth, but most appear later. When a neurofibroma is larger than the size of a pea, it’s likely that it’s growing on a group of nerves and it’s called a plexiform neurofibroma.
• Six or more café-au-lait spots on the skin. Spots are flat, light brown to dark brown in color, usually oval or circular in shape, and larger than 5 mm in size.
• Freckles in the armpits or in the groin that usually show up by the age of 5.
• Optic pathway glioma – a benign tumor on the optic nerve. Most have no symptoms, but some affect vision.
• Learning challenges.
• Bone deformities of the eye socket or tibia (a leg bone).
• Curvature of the spine (scoliosis).

Neurofibroma tumors are usually benign. In rare cases, they may become cancerous. Cancerous neurofibromas usually develop as malignant peripheral nerve sheath tumors (MPNST).

Symptoms of neurofibromatosis type 2 (NF2)

NF2 symptoms usually start during the late teens or during early adulthood. Neurofibromatosis type 2 is related to benign tumors called vestibular schwannomas that grow on nerves that connect the inner ears with the brain. Other types of tumors may grow on the brain or the spine.

People with NF2 may also develop cataracts or other eye problems that may cause vision problems. Sometimes they have numbness or weakness in the arms or legs. They may also have poor balance, seizures or skin tumors.

It’s unlikely that one person will have all the possible symptoms of NF1 or NF2, and both conditions may cause a range of neurofibromatosis symptoms ranging from mild to severe. In fact, about a third of people with neurofibromatosis don’t notice any symptoms.

If you’re wondering about your or your child’s potential NF1 or NF2 symptoms, make an appointment to consult with your doctor. They’ll work with you over time to come to an accurate diagnosis.

Conditions related to neurofibromatosis

People who have either NF1 or NF2 may also be at increased risk for some of the following disorders:

• Brain tumors such as gliomas, astrocytomas and ependymomas
• Sarcomas (many types)
• Breast cancer
• Endocrine cancers
• Melanoma
• Acute lymphoblastic leukemia
• Ovarian cancer
• Prostate cancer
• Meningioma
• Benign peripheral nerve sheath tumors
• Malignant peripheral nerve sheath tumors

Other names for neurofibromatosis

Neurofibromatosis type 1 (NF1) is also known as:

• Von Recklinghausen’s disease
• Von Recklinghausen’s phakomatosis
• Von Recklinghausen’s neurofibromatosis
• Neurofibroma, multiple
• Neurofibromatosis-pheochromocytoma-duodenal carcinoid syndrome
• Peripheral neurofibromatosis

Neurofibromatosis type 2 (NF2) is also known as:

• Bilateral acoustic neurofibromatosis
• Vestibular schwannoma neurofibromatosis
• Central neurofibromatosis

Diagnosis of neurofibromatosis types 1 & 2

When you see your doctor, they’ll start with a basic physical exam. They’ll ask about your medical history and potential neurofibromatosis symptoms. They’ll check for scoliosis, examine any café au lait spots or neurofibromas, and examine your eyes for Lisch nodules, cataracts or vision loss.

Your hearing and balance may be tested with electronystagmography or brainstem auditory evoked response. Doctors may order imaging tests such as X-ray, CT or MRI to find bone abnormalities or tumors in the brain, skull or spinal cord.

Genetic testing may be performed to test for any gene mutations that have been associated with NF1 or NF2. Genetic testing may not be conclusive because you can have neurofibromatosis without having an associated gene.

Confirming a diagnosis of NF1 or NF2 can be difficult because some neurofibromatosis symptoms change from year to year and some take years to develop. It takes a skilled and experienced clinician to sort through all the possibilities and discover whether you or your child has neurofibromatosis.

Treatments for neurofibromatosis

There’s no cure for NF1 or NF2, so neurofibromatosis treatment is aimed at minimizing symptoms. Medications can be prescribed for seizures, pain or other symptoms.

Café-au-lait spots don’t cause symptoms. If they affect appearance to the point where removing them is desirable, talk to your doctor about your options.

Surgery for neurofibromatosis treatment

The tumors associated with neurofibromatosis are usually benign but schwannomas and plexiform neurofibromas may rarely become cancerous. Some benign tumors cause symptoms if they grow big enough to put pressure on nerves, organs or other tissues. When these things happen, surgery or radiation may be used to remove the tumor and improve symptoms.

Radiation is sometimes preferred for tumor removal because it can be more precise and avoid causing more damage to nerves.

Any surgery or radiation for neurofibromatosis treatment needs to be weighed against the possibility that it will cause more damage to the nerves or tissues affected.

Ongoing treatment for neurofibromatosis

Both children and adults with NF1 or NF2 have regular checkups to follow symptoms and screen for evolving problems such as hearing loss, more tumors or tumor growth. Blood tests, X-rays or other tests may be recommended to check any other concerns.