Neurofibromatosis is a genetic disorder that disturbs cell growth in the nervous system causing tumors to form on nerve tissue. The tumors may develop anywhere in the nervous system including the brain, spinal cord and nerves. Neurofibromatosis is typically diagnosed in childhood or early adulthood.

The tumors are usually benign but in some cases they can become malignant or cancerous. The effects of neurofibromatosis may include hearing loss, learning impairment, heart and blood vessel complications, severe disability due to nerve compression by tumors as well as vision loss and severe pain.

Treatment for neurofibromatosis aims to maximize healthy growth and development and may include medications and surgery.



There are 3 different types of neurofibromatosis, each presenting with different symptoms.


Neurofibromatosis 1 (NF1)

  • Flat, light brown spots on the skin
  • Freckling in the armpits or groin area
  • Soft bumps on or under the skin (neurofibromas)
  • Tiny bumps on the iris of the eye (Lisch nodules)
  • Bone deformities
  • Learning disabilities
  • Abnormally large head size
  • Short stature


Neurofibromatosis 2 (NF2)

Symptoms of NF2 usually result from the formation of vestibular schwannomas (acoustic neuromas) in both ears that affect sound and balance information.


  • Gradual hearing loss
  • Ringing in the ears
  • Poor balance
  • Facial drop
  • Numbness and weakness in the arms or legs
  • Pain
  • Vision problems



Schwannomatosis is a rare form of neurofibromatosis that causes painful tumors to form on cranial, spinal and peripheral nerves but not on the nerve that carries sound and balance information from the inner ear to the brain. Schwannomatosis mainly causes chronic pain that can occur anywhere in the body.



Neurofibromatosis is caused by genetic defects (mutations). Each form of neurofibromatosis is caused by mutations in different genes.


Neurofibromatosis 1


The NF1 gene is located on chromosome 17. This gene produces a protein called neurofibromin, which is abundant in nervous system tissue and helps regulate cell growth. A mutation of the NF1 gene causes a loss of that protein allowing cells to grow rapidly.


Nurofibromatosis 2


The NF2 gene is located on chromosome 22 and produces a protein called merlin. The mutation of the NF2 gene causes a loss of merlin, which also causes uncontrolled cell growth.




Schwannomatosis may be linked to a mutation of the SMARCB1 gene located on chromosome 22. Schwannomatosis may be inherited or sporadic.


Risk factors

The biggest risk factor for neurofibromatosis is a family history of the disease. Approximately half of NF1 and NF2 cases are inherited. The remaining cases result from spontaneous mutations that occur at conception.

NF1 and NF2 are autosomal dominant disorders, meaning that one parent can pass the disorder to a child. It also means that each child has a 50% chance of inheriting the genetic mutation.



Complications of neurofibromatosis generally result from tumor growth that distorts nerve tissue or presses on internal organs.


Complications of neurofibromatosis 1 include:


  • Neurological problems: Learning and thinking difficulties and less commonly epilepsy, stroke and build up of excess fluid in the brain (hydrocephalus).


  • Concerns with appearance: Extensive light brown spots on the skin, numerous nerve tumors in the facial area.


  • Skeletal problems: Abnormally formed bones in children, curvature of the spine (scoliosis) and decreased bone mineral density that can lead to osteoporosis.


  • Visual difficulties: Tumors may form on the nerve leading from the eye to the brain (optic nerve).


  • Increase in neurofibromas: Puberty, pregnancy or menopause can cause an increase in neurofibromas.


  • Cardiovascular problems: Increased risk of high blood pressure and rarely blood vessel abnormalities.


  • Cancer: In rare cases, NF1 can cause development of cancerous tumors resulting from neurofibromas under the skin or plexiform neurofibromatosis involving multiple nerves.


Complications of neurofibromatosis 2 include:


  • Vestibular schwannomas in both ears
  • Partial or total deafness
  • Visual difficulties
  • Facial nerve damage
  • Skin lesions
  • Weakness or numbness in the extremities
  • Multiple benign brain tumors (meningiomas) or spinal tumors


Complications of schwannomatosis


The chronic pain caused by schwannomatosis can be debilitating and may require surgical treatment or pain management.


​​Cancer treatment

Malignant tumors and other cancer associated with neurofibromatosis are treated with usual cancer therapies including surgery, chemotherapy and radiation therapy.