What is neurofibromatosis type 2 (NF2)?
Neurofibromatosis type 2 (NF2) is a genetic disorder that involves changes in the NF2 gene. This particular gene helps in the production of merlin (also called schwannomin), a protein that stops tumors from forming. The gene is located on chromosome 22.
The main trait of NF2 is that noncancerous (benign) tumors grow on the nerves of the brain and the spine. In NF2, the auditory nerves, the ones that involve hearing, are commonly affected. Therefore, hearing is affected. These types of tumors grow along the auditory nerve that connects the brain and inner ear. The tumors are called vestibular schwannomas or acoustic neuromas.
Schwannomas are tumors that are made up of Schwann cells. Very often, the tumors grow on the auditory nerves on both the left and right side of the brain and are called bilateral vestibular schwannomas. These types of tumors are the main feature of NF2. These tumors often appear before the person reaches age of 30.
Tumors can appear on the skin and on other parts of the nervous system as well, such as the brain and spinal cord.
Who gets neurofibromatosis type 2 (NF2)?
Various estimates put the number of people worldwide born with NF2 at 1 in 25,000 to 1 in 40,000. Both males and females are affected in equal numbers. All ethnic groups are affected. It can be inherited, but about half the people with NF2 have no family history. Because it can be inherited, the main risk factor is family history.
Children with NF2 tend to have symptoms related to tumors in the brain and spinal cord. Adults diagnosed with NF2 are usually in the age range of 18 to 24 years old. They tend to have problems due to tumors on the auditory nerves.
Symptoms and Causes
What are the symptoms of neurofibromatosis type 2 (NF2)?
Early symptoms of NF2 include:
- Problems with balance (such as dizziness).
- Problems with hearing.
- Ringing in the ears, also called tinnitus.
For tumors that occur outside of the auditory nerves, symptoms might include:
- Weakness in the face, arms or legs.
- Clouded lenses in one or both eyes (cataracts), often at a young age.
- Increase in fluid on the brain.
Diagnosis and Tests
How is neurofibromatosis type 2 (NF2) diagnosed?
Your healthcare provider may suspect NF2 if there is a family history. Diagnosis depends on meeting certain criteria in terms of type and location of the tumors. Tests that might be done include:
- Magnetic resonance imaging (MRI) scan of the brain and spinal cord to determine the location of the tumors.
- Hearing tests.
- Vision tests.
- Genetic testing.
Management and Treatment
How is neurofibromatosis type 2 (NF2) managed?
Currently, NF2 can’t be cured. Treatment involves monitoring. People with this condition are likely to have yearly MRI scans and hearing and vision tests as needed.
Cataracts might be treated by surgery.
How is a neurofibromatosis type 2 (NF2) tumor treated?
Treatment of tumors varies. Some tumors aren’t treated at all. Some, depending on size and location, might be treated with radiation or removed during surgery. As with any type of treatment, the benefits must outweigh the risks for each option.
Tumors affecting hearing: Schwannomas are common noncancerous tumors that affect the auditory nerve. Hearing loss is a significant risk. Treatment of these tumors can involve surgery or radiation therapy (possibly Gamma Knife®), depending on size and symptoms. Gamma Knife is a single high dose radiation delivered to the tumor. Hearing loss might be treated with hearing aids if the auditory nerve has not been removed. An auditory brainstem implant device is considered if you have hearing loss but still have part of your auditory nerve intact.
Tumors affecting the spine: The tumors can be in the spinal cord (intramedullary) or outside the spinal cord (extramedullary). Common types of intramedullary tumors include ependymomas and astrocytomas. Common extramedullary tumors include schwannomas and meningiomas.
Meningiomas are tumors that arise from the meninges or covering of the brain and spine. They are seen in over 50% of NF2 patients. Multiple meningiomas may be treated with surgery, radiation therapy, or chemotherapy depending on a host of factors.
Can neurofibromatosis type 2 (NF2) be prevented?
Genetic counseling can be helpful to people with a family history of this condition.
Where can I learn more about neurofibromatosis?
Visit Cleveland Clinic Children's Neurofibromatosis Center website or call 216.442.5069 or 800.233.2273 ext. 25069.
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