This genetic condition causes tumors to form on nerves throughout the body, often showing up as skin changes. The right treatment and management approach can help address symptoms and potential complications.

Neurofibromatosis (NF) is a genetic disorder characterized by the growth of tumors on the nerves throughout the body. The disease can also affect the skin and cause bone deformities.

There are two main forms:

  • neurofibromatosis type 1 (NF1), historically known as von Recklinghausen’s disease
  • neurofibromatosis type 2 (NF2)

A third disorder, called schwannomatosis, is a related but distinct disease.

The most common form is NF1. It affects about 1 in 3,000 people.

NF1 causes tumors called neurofibromas in the tissues and organs of the body. Most often, these tumors are non-cancerous. However, for some, they can become cancerous. Management of this disease focuses on managing symptoms and monitoring tumors for changes.

NF1 affects the skin and the peripheral nervous system. The first symptoms usually appear in childhood and affect the skin.

Symptoms of NF1 include:

  • café-au-lait spots, which are tan spots in different sizes and shapes, often found in multiple places
  • freckles, especially those in clusters under the arms or in the groin
  • neurofibromas, or non-cancerous tumors that grow around nerves
  • plexiform neurofibromas, or larger growths that affect the bones, muscles, and other tissue
  • Lisch nodules, or growths that affect the colored part of the eyes (iris)
  • a type of tumor in the optic nerve known as a glioma
  • bone problems, including a curved spine (scoliosis) or leg bones
  • learning issues in childhood, including attention deficit hyperactivity disorder (ADHD) or challenges with reading or math
  • size differences, including a larger head or shorter height than average

The cause of NF1 is a genetic mutation. Mutations are changes in your genes. The genes make up your DNA, which defines every physical aspect of your body.

In NF1, a mutation occurs on the NF1 gene, causing an increase in the development of cancerous and noncancerous tumors.

About half of those who have NF1 inherited the disease from a parent. However, the other half of people with NF1 develop it from a spontaneous gene mutation.

Diagnosis depends on family history and the presence of specific symptoms, such as:

  • six or more café-au-lait spots (larger in 5mm in children or 15mm post-puberty)
  • two or more neurofibromas or one plexiform neurofibroma
  • freckles in the underarm or groin area
  • an optic nerve glioma
  • two or more Lisch nodules
  • bone changes

Your doctor may consider an NF1 diagnosis if you have:

  • a family history of NF1 and one or more of these symptoms
  • no family history of NF1 and two or more of these symptoms

However, your doctor must also rule out other diseases that can cause tumors.

Illnesses that resemble NF1 include:

  • constitutional mismatch repair deficiency
  • Legius syndrome
  • McCune-Albright syndrome
  • Noonan syndrome

Genetic testing can help pinpoint the diagnosis.

Testing for cancer

Most NF1 tumors are not cancerous. Only about 10% of those with the disease will develop a cancerous tumor. These tumors, called malignant peripheral nerve sheath tumors, can grow quickly and spread to other areas, making early diagnosis and treatment essential.

To check for the presence of cancer, your doctor may need to remove skin tissue or tumor samples fore testing.

Conditions linked with NF1

Certain health conditions often co-exist with NF1, including:

  • scoliosis
  • hypertension
  • learning disabilities
  • ADHD

If your doctor diagnoses NF1, they may be on the lookout for these conditions, which require routine monitoring.

NF1 is a complex illness. The right treatment and management approach can help address symptoms and potential complications.

Routine monitoring is a main part of ongoing treatment, and may include:

  • regular blood pressure checks
  • annual exams with an NF1 specialist
  • annual eye exams
  • evaluations for developmental delays or disorders in children

Treatment can include:

  • watchful waiting, where doctors monitor tumors for potential problems over time
  • surgery, where tumors that cause issues are removed
  • medication, such as selumetinib (Koselugo) or mirdametinib (Gomekli), to shrink or slow the growth of symptomatic plexiform neurofibromas that cannot be surgically removed in children with NF1
  • therapeutic support services and devices, such as speech therapy, hearing aids, or mobility devices

If an NF1 tumor becomes cancerous, it may need additional treatment with chemotherapy, radiation, or surgery.

NF1 increases your risk for cancer. You should have tumors checked regularly by your doctor. They will look for any changes that indicate cancer. Early diagnosis of cancer leads to a better chance for remission.

People with NF1 may have large tumors on the body. Removal of visible tumors on the skin can help with self-esteem.

NF1 is a genetic disease. If you have NF1, you can pass it to your children. You should visit a genetic counselor before having children. A genetic counselor can explain the odds of your child inheriting the disease.

Neurofibromatosis type 1 (NF1) is a genetic disorder that causes noncancerous tumors to grow on nerves throughout the body, often affecting the skin, bones, and eyes. Symptoms usually appear in childhood and can include café-au-lait spots, nodules, and scoliosis.

Although most NF1 tumors are not cancerous, regular checkups are important, as some tumors may become cancerous later. With ongoing care, many people with NF1 can manage their symptoms and maintain a good quality of life.