Neurofibromatosis type 1 (NF1) and NF2-related schwannomatosis (NF2-SWN): What to know after diagnosis

Learning that you have neurofibromatosis type 1 (NF1) or NF2-related schwannomatosis (NF2-SWN) may raise questions and concerns.

NF1 and NF2-SWN are separate conditions linked to changes in certain genes.

NF1 symptoms often begin in early childhood. NF1 commonly causes changes in the skin, called cafe au lait spots. These spots are flat and look darker than the surrounding skin. Their color may range from tan to deep brown, depending on a person’s skin tone. NF1 also can be linked to tumors in the brain or spinal cord. These tumors are often benign. This means the tumors are not cancerous. However, some NF1-related tumors can become cancerous

NF2-SWN symptoms typically start in the late teens or early adulthood. NF2-SWN often causes tumors to grow on the nerves linked to hearing and balance. This may lead to hearing loss and trouble with balance. People who have NF2-SWN also may have tumors that grow in their brains, spines or nerves. NF2-SWN used to be called neurofibromatosis type 2. Its name was changed to NF2-related schwannomatosis to show that it belongs to a group of conditions that mainly cause schwannomas. A schwannoma is a type of tumor linked to the nerves.

NF1 and NF2-SWN are considered rare conditions. This article answers common questions people have about NF1 and NF2-SWN.

Seeing the words "genes," "deoxyribonucleic acid (DNA)" and "chromosomes" on a lab report can be confusing.

Genes are sections of DNA. They give your cells instructions for how to grow and work. They are carried on chromosomes.

The gene linked to NF1 gene on chromosome 17, and the gene linked to NF2-SWN is on chromosome 22. If a disease-causing change happens, it may cause NF1 or NF2-SWN depending on which gene the change is linked to.

Genetic test results may give clues to your healthcare team about what symptoms and health risks are possible. But the results often cannot predict every NF1 or NF2-SWN symptom or how NF1 or NF2-SWN may change over time.

When people learn they have NF1 or NF2-SWN, they may wonder how it happened.

About half of people who have NF1 or NF2-SWN inherit the disease-causing gene change from a parent. But that does not mean you will have the same NF1 or NF2-SWN symptoms that others NF1 and NF2-SWN have. Symptoms can vary even among family members.

NF1 symptoms can vary and may include:

• Cafe au lait spots. These spots are flat and look darker than the surrounding skin. Their color may range from tan to deep brown, depending on a person’s skin tone. They may be present at birth or appear during the first years of life. After childhood, new spots typically stop appearing. People with NF1 usually have more than six of these spots.
• Freckling in the armpits or groin area. These freckles are smaller than cafe au lait spots.
• Tiny bumps on the iris of the eye, called Lisch nodules. The iris is the colored part of the eye. These bumps don't affect vision.
• Soft bumps on or under the skin, called neurofibromas. These tumors usually grow on or under the skin. Usually, a neurofibroma is benign, but some deeper plexiform neurofibromas can cause problems.
• Bone changes. NF1 may cause bone issues. People with NF1 may have a curved spine condition called scoliosis.

NF2-SWN symptoms often result from slow-growing tumors in the ears. These tumors are known as vestibular schwannomas. These tumors are often benign.

NF2-SWN symptoms often begin in the late teens. They usually depend on where the tumors are growing and may include:

• Hearing loss.
• Tinnitus, also known as ringing in the ears.
• Poor balance.
• Headache.

People with NF2-SWN usually have fewer cafe au lait spots compared with people with NF1.

Some people with NF2-SWN have small lumps or bumps on their bodies. These are usually caused by tumors growing on nerves under the skin.

Tumors on the facial nerve may weaken facial muscles. This can make it hard to smile, blink or move one side of the face.

The main tumors linked to NF1 are neurofibromas:

Most neurofibromas are benign.

• A neurofibroma that grows on the skin is called a cutaneous neurofibroma.
• A neurofibroma that grows beneath the skin is called a subcutaneous neurofibroma.
• A neurofibroma that grows along multiple branches of a nerve is called a plexiform neurofibroma. Some plexiform neurofibromas can turn cancerous.

NF1 also is linked to optic gliomas and other gliomas.

The main tumors linked to NF2-SWN are vestibular schwannomas. These tumors grow on nerves linked to hearing and balance. NF2-SWN often causes a vestibular schwannoma in both ears.

NF2-SWN also can cause:

• Schwannomas on nerves in the head, along the spine and in other parts of the body.
• Meningiomas may grow from the coverings of the brain or spinal cord.
• Ependymomas may grow within the spinal cord.

NF2-SWN-related tumors are often benign. But their number and location may affect hearing, balance or nerve function.

An NF1 diagnosis often starts with a physical exam and a review of your personal and family medical history. A healthcare professional checks your skin for cafe au lait spots. These spots usually are one of the first NF1 symptoms to appear. Healthcare professionals generally look for at least two NF1 signs or symptoms if they suspect that a person has NF1.

Healthcare professionals also may order the following tests:

• An eye exam. An eye exam can show whether Lisch nodules are present. It also can detect vision changes that may be caused by an optic pathway glioma.
• Imaging tests. Imaging tests may be ordered to get more information about specific symptoms or findings. For example, magnetic resonance imaging (MRI) can provide clues about a suspected optic pathway glioma or other types of tumors. X-rays may be used to look for certain bone changes.
• Genetic tests. A health professional may advise genetic testing when cafe au lait spots and skin-fold freckling are present.

NF2-SWN also is often diagnosed through a physical exam, tests, and a review of personal and family medical history. The results may help find early signs of NF2-SWN complications, such as hearing loss and balance changes.

Tests may include:

• An eye exam. An eye exam may show early changes such as cataracts. Some people with NF2-SWN develop cataracts at a young age. Cataracts cloud the lens of the eye and may cause changes in vision.
• Hearing and balance tests. Sometimes people are diagnosed with NF2-SWN after they start having hearing loss, ringing in the ears or trouble with balance. These are often the first signs of vestibular schwannomas. Auditory brainstem response and vestibular testing can show whether the hearing and balance nerves are sending signals properly.
• Imaging tests. A brain MRI may find vestibular schwannomas in the ears. A spine MRI may find spinal schwannomas, meningiomas and ependymomas within the spinal cord. An MRI may detect tumors before symptoms appear.
• Genetic tests. Genetic testing looks for a disease-causing change in the gene linked to NF2-SWN.

Imaging may show neurofibromas along nerves or thickening or swelling around the optic nerves.

Imaging may show vestibular schwannomas in the small bony passages between the inner ears and the brain. It also may show schwannomas on other nerves, meningiomas attached to the coverings of the brain or spinal cord, and ependymomas growing within the spinal cord.

Whether you are diagnosed with NF1 or NF2-SWN, talk with your healthcare team about what to expect. The team can explain your treatment options and how each option may affect your care.

NF1 treatment often includes regular follow-up visits with your healthcare team based on your symptoms and health risks.

If symptoms are bothersome, treatment may include:

• Medicines. Medicines may treat tumors such as plexiform neurofibromas that grow in multiple nerves. The medicines can shrink the size of a tumor.
• Surgery. If surgery is an option, removing all or part of a tumor that presses on nearby tissues or organs may ease symptoms.
• Cancer treatments. In addition to advising surgery, your healthcare team also may consider chemotherapy or radiation therapy.

Because NF2-SWN may cause tumors over time, lifelong follow-up with your healthcare team is important. Treatment for NF2-SWN often focuses on protecting balance, hearing and nerve function. Treatment may include surgery and radiation therapy.

Surgery may be advised for tumors that grow quickly, cause pain, or affect hearing or balance. The goal is to remove as much tumor as possible while protecting nearby nerves. Sometimes, surgery may not be possible.

When surgery is not possible, your care team may consider stereotactic radiosurgery. This treatment uses precisely targeted radiation to stop or slow tumor growth.