Neurofibromatosis Type 2 (NF2)

Neurofibromatosis type 2 (NF2) is a rare genetic disorder characterized by the growth of noncancerous tumors throughout the nervous system, particularly in the brain and spinal cord.

Causes and Genetics

NF2 is caused by a mutation in the NF2 gene, which provides instructions for making a protein called merlin or schwannomin. This protein acts as a tumor suppressor, helping to regulate cell growth and division. The mutation leads to the production of a nonfunctional protein, resulting in uncontrolled cell growth and tumor formation.

NF2 is inherited in an autosomal dominant pattern, meaning that a single copy of the mutated gene is sufficient to cause the condition. Each child of an affected parent has a 50% chance of inheriting the mutated gene.

Symptoms

The symptoms of NF2 typically begin in late childhood or early adulthood and may include:

• Hearing loss, which can be progressive and lead to deafness
• Balance problems and dizziness (vestibular dysfunction)
• Tinnitus (ringing or other sounds in the ears)
• Weakness or numbness in the face, arms, or legs
• Difficulty with speech and swallowing
• Headaches and seizures
• Skin tumors or nodules

Diagnosis

Diagnosis of NF2 is based on a combination of clinical evaluation, imaging studies, and genetic testing. The diagnostic criteria for NF2 include:

• Bilateral vestibular schwannomas (tumors on both auditory nerves)
• Family history of NF2
• Presence of multiple meningiomas (tumors in the membranes surrounding the brain and spinal cord) or ependymomas (tumors in the spinal cord)
• Genetic testing to identify a mutation in the NF2 gene

Treatment and Management

Treatment for NF2 is typically focused on managing symptoms and preventing complications. This may include:

• Surgery to remove tumors, particularly vestibular schwannomas
• Radiation therapy to slow tumor growth
• Physical therapy to improve balance and mobility
• Audiological rehabilitation to address hearing loss
• Pain management for chronic pain

Prognosis

The prognosis for individuals with NF2 varies depending on the severity of symptoms, the number and location of tumors, and the effectiveness of treatment. With proper management, many people with NF2 can lead active and productive lives, although they may experience significant disability and reduced life expectancy.