Schwannomatosis
How common is schwannomatosis?
What causes schwannomatosis?
How is schwannomatosis diagnosed?
How is schwannomatosis treated?
Where can I get more information about schwannomatosis?
What is schwannomatosis?
Schwannomatosis is a rare form of neurofibromatosis. People with this condition develop benign (non-cancerous) nerve tumors, called schwannomas. The tumors in this condition most often affect the spinal cord and nerves to the body. However, unlike neurofibromatosis, type 2, tumors do not usually form on the nerves in the ear (vestibular nerves). Features vary between people who have this condition. For many individuals the condition can be very painful.
How common is schwannomatosis?
This condition affects fewer than 1 in 40,000 people. Most people are adults when the diagnosis is made.
What causes schwannomatosis?
Schwannomatosis is a genetic condition, but it does not usually follow a clear pattern of inheritance. Most people are the only one in their family with the condition. Genetic changes (mutations) in at least three different genes, SMARCB1, LZTR1, and COQ6, have been found in individuals and families with schwannomatosis. However, a mutation in any one of these genes is not enough to cause the condition. More genetic changes are needed in a cell for a schwannoma (nerve tumor) to form.
How is schwannomatosis diagnosed?
The diagnosis is made when a person is found to have two or more schwannomas that do not affect the nerves in the ear. If there is a family history of schwannomatosis, the diagnosis may be made after only one tumor is detected.
Genetic testing - Genetic testing can be done on the genes associated with schwannomatosis, but testing does not find a mutation in everyone with this diagnosis. In some people, other genes may be responsible for the condition that have not yet been discovered. It is also important to know that finding a mutation in one of the genes does not mean that the person will develop tumors.
How is schwannomatosis treated?
There is currently no cure for schwannomatosis and no medications to treat schwannomas. Surgery to remove tumors can sometimes help. Pain often goes away when a tumor can be completely removed, but the pain may come back if new tumors form. When surgery cannot be done, treatment at a pain clinic may help with pain control. Kaiser Permanente in Northern California provides specialty care for people with schwannomatosis at the Regional Neurofibromatosis Program.
Where can I get more information about schwannomatosis?
NIH: Genetics Home Reference on schwannomatosis - General information about this condition provided as a service of the U.S. National Library of Health. Links to related sites are included on the page. https://ghr.nlm.nih.gov/condition/schwannomatosis
Family Support Resources
Children’s Tumor Foundation: http://www.ctf.org/
Schwannomatosis brochure (From ctf.org): Newly Diagnosed with Schwannomatosis
Neurofibromatosis Network: https://nfnetwork.org/
Last reviewed: February 15, 2018
Reviewed by: Kimberly Barr, MS, LCGC