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.
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.
by NF Midwest and the NF2 Crew
The Genetics of Neurofibromatosis-2 (webinar)
presented by NF Network 2013
Volumetric Measurement in Neurofibromatosis
by Diana Haberkamp, reviewed by Eva Dombi, MD
Technology and NF2
transcript of presentation by NF Mid-Atlantic 2013
Review and chart of applications to support spoken communication and hearing loss
review of Apple apps to support hearing loss by Berner and Smart 2013
Consensus Recommendations for Current Treatments and Accelerating Clinical Trials for Patients With Neurofibromatosis Type 2
from The American Journal of Medical Genetics (Sep 2011)
NF Network webinar transcript (Feb 2012)
Auditory Brain Implant (ABI) and Cochlear Implant (CI) (webinar)
presented by the NF Network with Dr. William Slattery, House Ear Institute, California
Ocular Manifestations of Neurofibromatosis: Relief for Dry Eyes
NF Midwest Symposium Transcript Presented by Louise A. Sclafani, OD, FAAO 2012
Mutations and Biological Behavior of NF2-Associated Schwannomas and Meningiomas and Potential Therapies
Long-Sheng Chang, Phd, The Research Institute at Nationwide Children’s Hospital and Ohio State University College of Medicine Transcript(2014)
Patient-Centered Research in NF2: Improving Quality of Life
Amanda Bergner, MS, CGC, Johns Hopkins Transcript (2013)
Research Advances in Neurofibromatosis Type 2
from NF Network webinar with Ashok Asthagiri, M.D. (Jan 2013)
Identification and Development of Therapeutic Targets in Neurofibromatosis Type 2
Joseph Kissil, NF Midwest Transcript (2013)
by Ashok R. Asthagiri, M.D., HHS/NIH/NINDS NF Midwest Symposium Transcript (2011)
NF2 Research at Massachusetts General Hospital
Vijaya Ramesh, Ph.D NF Midwest Symposium Transcript (2010)
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.
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