Neurofibromatosis type 2 (NF2) is a disorder that causes noncancerous tumors to grow in the nervous system. Most individuals develop tumors called vestibular schwannomas or acoustic neuromas that grow on the hearing and balance nerves in the brain.
Symptoms of NF2 typically remain dormant until adolescence or in a person’s early twenties, but they can begin at any age. The most common problems caused by NF2 are severe hearing loss, ringing in the ears (tinnitus), and balance problems. Most people develop tumors in both ears by the age of 30 and eventually become fully deaf.
They are at a high risk of developing another type of brain tumor known as a meningioma and can grow tumors throughout the nervous system, particularly on the spine. The effects of each tumor vary based on location in the body.
Other complications such as vision loss, numbness, or weakness in the arms or legs, facial paralysis, fluid buildup in the brain, and cataracts are also possible.
Source