Affecting approximately one in 25,000 people, Neurofibromatosis Type 2 is caused by a mutation in a gene on chromosome 22.
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.
Recent studies estimate that the incidence of neurofibromatosis type 2 may be as high as 1 in 25,000 people.
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.
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.
For more information about naming genetic conditions, see the Genetics Home Reference Condition Naming Guidelines and How are genetic conditions and genes named?.
NF Midwest has a special group called the NF 2 Action Group (NF2ACT). This is a committee of people who have NF2 in the family and a vast amount of experience. Let us know if you would like us to put you in touch with them.
NF Midwest Symposium and iNFo Fair
By Jackie Diels, OT
By Berner and Smart
Review of Apple apps to support hearing loss
Transcript of presentation
In June of 2013, NF Network presented a captioned webinar "The Genetics of…
NF Midwest and the NF2 Crew
By Diana Haberkamp, reviewed by Eva Dombi, MD
NF Network | 2012
By Dr. Andrew Fishman
American Journal of Medical Genetics | 2011
A self-help, support, and social advocacy group giving a voice to people with…
Neurofibromatosis Type 2 support community
NF Network By Dr. William Slattery, House Ear Institute, California
Watch a recording of the neurofibromatosis 2 webinar about Auditory Brain Implant (ABI) and…
By Derald E. Brackmann, M.D. of the House Ear Institute
By Louise A. Sclafani, OD, FAAO
NF Midwest Symposium Transcript
By Vijaya Ramesh, Ph.D
By Ashok R. Asthagiri, M.D.
HHS/NIH/NINDS Symposium Transcript
By Joseph Kissil
At NF Midwest's annual family symposium held on October 12, 2013, Dr. Joseph…
By Ashok Asthagiri, M.D.
The Research Institute at Nationwide Children’s Hospital and Ohio State University College of Medicine Transcript
By Long-Sheng Chang, Phd
The resources on this site should not be used as a substitute for professional medical care or advice on Neurofibromatosis. Users seeking information about a personal genetic disease, syndrome, or condition should consult with a qualified healthcare professional.