What Is Schwannomatosis?
Schwannomatosis is a rare form of neurofibromatosis that affects approximately 1 in 40,000 individuals. Patients with schwannomatosis develop tumors called schwannomas, which can be present on almost any nerve in the body. These tumors often cause chronic pain, which may be the presenting feature in a patient with schwannomatosis. Other neurological features, such as tingling or numbness, also may occur.
There are several differences between NF1, NF 2, and schwannomatosis. One main difference between NF2 and schwannomatosis is that patients with schwannomatosis do not develop the eighth cranial nerve tumors that characterize NF2. In addition, other types of tumors that can be seen in NF2 (e.g., meningiomas, ependymomas, astrocytomas) are not present in schwannomatosis. Other features of NF1 (e.g., learning problems, café au lait spots) are not present in schwannomatosis either. Finally, patients with schwannamotosis do not have the visible skin tumors that are present in NF1 and some NF2 patients.
There is genetic testing available for schwannomatosis. This testing is for a gene called INI1. The genetics and inheritance of schwannomatosis are much more complicated and less clear than the genetics of NF1 or NF2, however.