Reviewed March 2007
What is neurofibromatosis type 2?
Neurofibromatosis type 2 is a disorder characterized by the growth of noncancerous tumors in the nervous system. The most common tumors associated with neurofibromatosis type 2 are called vestibular schwannomas or acoustic neuromas. These growths develop along the nerve that carries information from the inner ear to the brain (the auditory nerve). Tumors that occur on nerves in other areas of the brain or spinal cord are also commonly seen with this condition.
The signs and symptoms of this condition usually appear during adolescence or in a person's early twenties, although onset can occur at any age. The most frequent early symptoms of vestibular schwannomas are hearing loss, ringing in the ears (tinnitus), and problems with balance. In most cases, these tumors occur in both ears by age 30. If tumors develop in other parts of the brain or spinal cord, signs and symptoms vary according to their location. Complications of tumor growth can include changes in vision or sensation, numbness or weakness in the arms or legs, and fluid buildup in the brain. Some people with neurofibromatosis type 2 also develop clouding of the lens (cataracts) in one or both eyes, often beginning in childhood.
How common is neurofibromatosis type 2?
Recent studies estimate that the incidence of neurofibromatosis type 2 may be as high as 1 in 25,000 people.
What genes are related to neurofibromatosis type 2?
Mutations in the NF2 gene cause neurofibromatosis type 2.
The NF2 gene provides instructions for making a protein called merlin (also known as schwannomin). This protein is produced in the nervous system, particularly in Schwann cells, which surround and insulate nerve cells in the brain and spinal cord. Merlin acts as a tumor suppressor, which means that it keeps cells from growing and dividing too rapidly or in an uncontrolled way. Although its exact function is unknown, this protein is likely also involved in controlling cell movement, cell shape, and communication between cells. Mutations in the NF2 gene lead to the production of a nonfunctional version of the merlin protein that cannot regulate the growth and division of cells. Research suggests that the loss of merlin allows cells, especially Schwann cells, to multiply too frequently and form the tumors characteristic of neurofibromatosis type 2.
Read more about the NF2 gene.
How do people inherit neurofibromatosis type 2?
Neurofibromatosis type 2 is considered to have an autosomal dominant pattern of inheritance. People with this condition are born with one mutated copy of the NF2 gene in each cell. In about half of cases, the altered gene is inherited from an affected parent. The remaining cases result from new mutations in the NF2 gene and occur in people with no history of the disorder in their family.
Unlike most other autosomal dominant conditions, in which one altered copy of a gene in each cell is sufficient to cause the disorder, two copies of the NF2 gene must be altered to trigger tumor formation in neurofibromatosis type 2. A mutation in the second copy of the NF2 gene occurs in Schwann cells or other cells in the nervous system during a person's lifetime. Almost everyone who is born with one NF2 mutation acquires a second mutation in many cells and develops the tumors characteristic of neurofibromatosis type 2.
Where can I find information about treatment for neurofibromatosis type 2?
These resources address the management of neurofibromatosis type 2 and may include treatment providers.
You might also find information on treatment of neurofibromatosis type 2 in
Educational resources and Patient support.
Where can I find additional information about neurofibromatosis type 2?
You may find the following resources about neurofibromatosis type 2 helpful. These materials are written for the general public.
You may also be interested in these resources, which are designed for healthcare professionals and researchers.
What other names do people use for neurofibromatosis type 2?
- Bilateral Acoustic Neurofibromatosis
- Central Neurofibromatosis
- Familial Acoustic Neuromas
- Neurofibromatosis 2
- Neurofibromatosis Type II
- Schwannoma, Acoustic, Bilateral
What if I still have specific questions about neurofibromatosis type 2?
Where can I find general information about genetic conditions?
The Handbook provides basic information about genetics in clear language.
These links provide additional genetics resources that may be useful.
What glossary definitions help with understanding neurofibromatosis type 2?
The resources on this site should not be used as a substitute for
professional medical care or advice. Users seeking information about
a personal genetic disease, syndrome, or condition should consult with a qualified
See How can I find a genetics professional in my area? in the Handbook.