Neurofibromatosis Type 1

Neurofibromatosis is a genetic disorder that causes tumors in the nervous system. Tumors develop in the nerves or the tissue that surrounds the nerves, called myelin sheath. Specifically affected genes determine the type of neurofibromatosis:

  • Neurofibromatosis type 1 (NF1)
  • Neurofibromatosis type 2 (NF2)
  • Schwannomatosis

NF1 is the most common type of neurofibromatosis that affects the nerves outside the brain and spinal cord, called peripheral nerves.

Causes of NF1

NF1 is caused by a change in a specific gene. The gene normally makes proteins that help control growth in the nerves. Since the gene is defective, these proteins are not able to control growth and tumors develop.

You may be at risk for NF1 if you inherit the abnormal gene from a parent. You have a 50% chance of passing off the gene to your children. However, you can also develop NF1 without a family history of the gene.


Most symptoms begin between birth and age 10. NF1 may cause:

  • Light brown spots (café-au-lait spots) on the skin
  • Freckles in the armpits or groin
  • Larger than normal head circumference in children
  • Shorter than normal stature in children
  • Problems with growth of spine (scoliosis), bones of skull or shin bones

Other medical conditions associated with NF1 include:

  • Mild impairment of intellectual function, learning disabilities (ADHD)
  • Seizures
  • Headaches
  • Congenital heart defects or damaged blood vessels
  • High blood pressure


You doctor may suspect NF1 if you have a history of:

  • Neurofibromas (tumors that grow on a nerve or nerve tissue). These tumors rarely occur before puberty and can progress to become aggressive malignant tumors.
  • Growths on the iris of the eye (Lisch nodules or hamartomas)
  • Tumor on the optic nerve that may affect vision (optic nerve gliomas)

Your doctor may conduct an MRI scan to create image of the nerves and brain to look for tumors. Your doctor may also send samples of the tumors for a biopsy.

We recommend genetic testing for families with a history of neurofibromatosis.

Treatment for NF1

There are no current treatments to stop the tumors from growing. You may not need any treatment since these tumors are rarely cancerous, grow slowly and may not cause problems. You should visit your doctor for regular exams to check for new tumors or symptoms.

You may require surgery to remove painful or disfiguring tumors. Your doctor can prescribe medications and therapies to manage your symptoms such as seizures and learning disabilities.

Rarely, some tumors can become cancerous. These tumors may need to be treated with surgery, chemotherapy or radiation.


Content was created using EBSCO’s Health Library. Edits to original content made by Rector and Visitors of the University of Virginia. This information is not a substitute for professional medical advice.