Neurofibromatosis (NF) refers to a group of three genetic syndromes, type 1 (NF1), type 2 (NF2) and schwannomatosis. NF causes tumors that can affect the nervous system. The tumors can develop on the brain, nerves or spinal cord. In some cases, they can become cancerous, but most often they are benign. However, these tumors can lead to bone deformities, problems with vision, hearing and balance and other health conditions.
Both NF1 and NF2 are present at birth. NF1 is usually diagnosed in childhood, while NF2 and schwannomatosis are more often diagnosed in early adulthood. There’s no known way to prevent neurofibromatosis.
Michael Avery, MD, a neurosurgeon with Banner Brain & Spine, said that people with NF need care from a multidisciplinary team. That team can include neurosurgeons, ENTs, dermatologists, ophthalmologists, oncologists and radiation oncologists. Dr. Avery told us more about these three conditions.
Neurofibromatosis type 1 (NF1)
NF1 is the most common type of neurofibromatosis. It’s caused by a genetic mutation in the NF1 gene that affects a protein called neurofibromin, and it strikes about 1 in 3,500 people. If you have this condition, you have a 50% chance of passing it on to a child. But 50% of cases occur in children with no family history.
Children with NF1 usually have signs soon after birth that can include:
- Light brown spots on the skin, called café-au-lait spots
- Freckles in the armpits or groin
- Small tumors on the nerves under the skin that cause bumps, called cutaneous neurofibromas
- Tan spots on the colored part of the eye, called Lisch nodules
- Tumors on the optic nerve, called optic pathway glioma, that can affect vision
- Bone deformities, often on the shin bone or the back of the eye socket
They may also have:
- Short stature
- A large head
- Heart defects or high blood pressure
- Cancerous nervous system tumors, such as malignant peripheral nerve sheath tumor
- Gastrointestinal tumors
- Adrenal gland tumors
- Intellectual or learning disabilities—usually these are mild
- Curvature of the spine (scoliosis)
- Attention deficit hyperactivity disorder (ADHD)
“People with NF1 need to be monitored regularly to watch for tumors that are growing, new tumors that are developing, or tumors that are becoming cancerous,” Dr. Avery said. Worrisome tumors can sometimes be removed surgically. Tumors on the optic nerve can also be treated with chemotherapy since with surgery there’s a risk of causing blindness. A drug called Selumetinib (Koselugo) can also help keep tumors from growing.
If you or your child has this condition, it’s crucial to watch your skin for signs of changes and see your specialists regularly. “Most people with NF1 have a normal life expectancy if they are monitored closely,” Dr. Avery said.
Neurofibromatosis type 2 (NF2)
NF2 is the second most common type of neurofibromatosis, but it’s much less common than NF1, affecting about 1 in 35,000 people. A mutation in the NF2 gene causes it. As with NF1, you have a 50% chance of passing it to a child. But 50% of cases occur in children with no family history.
People with NF2 may have noncancerous tumors on the nerves in the brain, the covering of the brain and spinal cord, and the peripheral nerves. The condition often affects the nerve that is responsible for hearing and balance. So, people with this condition may have gradual hearing loss.
Some people develop ringing in the ears, called tinnitus, and/or progressive hearing loss. “Tumors called vestibular schwannomas often develop that affect both ears, so the major goal is to preserve hearing in at least one of the ears. That may require surgery while the tumor is still small since when you remove larger tumors, you risk permanent hearing loss,” Dr. Avery said. People with NF2 may need to consider hearing aids or cochlear implants.
The tumors that affect the covering of the brain and spinal cord, called meningiomas, can cause symptoms if they grow large and press on the nervous system. People with NF2 may also develop cataracts, which can cause gradual vision loss.
“Like NF1, this condition requires regular monitoring by various specialists,” Dr. Avery said. Often, tumors don’t cause problems and can simply be watched to see if they grow. And those that do can usually be removed surgically.
Radiation may be a good option for tumors that can’t be operated on or that recur after surgery. And various chemotherapy options are being tried as well.
Schwannomatosis
Schwannomatosis is the least common type, affecting about 1 in 40,000 people. It’s also caused by a genetic mutation and may be inherited from a parent. It’s related to NF2 and, like NF2, it causes multiple tumors throughout the body. But people with schwannomatosis don’t develop the tumors that can cause hearing and balance problems.
People with schwannomatosis need to be closely monitored by their medical team to watch for new and growing tumors. Treatment options are similar to those for NF2—surgery for tumors that are causing issues and radiation and, potentially, chemotherapy for those that can’t be operated on.
The bottom line
Neurofibromatosis refers to three types of genetic conditions that can cause tumors. The tumors are usually not cancerous, but they can lead to hearing, balance, vision and other problems, so they may need to be monitored. To learn more about neurofibromatosis and treatments for this condition, visit the Children’s Tumor Foundation and reach out to a medical professional at Banner Health.
