NF1—caused by mutations (or changes) of the neurofibromin gene (more common)
NF2—caused by mutations of the merlin gene
NF is caused by a change in a gene. In many cases the abnormal gene is inherited. However, frequently the gene changes occur by chance in a person with no family history of NF. A person with the inherited form of NF has a 50% chance of passing on the abnormal gene each time he or she has a child. Also, all first-degree relatives (parents, children, and siblings) of an affected individual should be considered at risk and evaluated for signs of NF.
The main risk factor for NF is having a family member with the disease.
NF1 and NF2 have different symptoms. With either type, the symptoms can range from mild to severe. In most cases, the symptoms are mild and may be overlooked.
Symptoms of NF1
Light brown spots (called café-au-lait spots) on the skin
Neurofibromas (tumors that grow on a nerve or nerve tissue)— rarely occur before puberty
Most of these symptoms begin between birth and age 10.
Symptoms of NF2
Several tumors on the nerves of the brain and spine—Most common are tumors that affect the nerves to the ears. Hearing loss may begin as early as the teen years.
Other symptoms may include:
(ringing in the ear)
Pain or numbness in the face
The doctor will ask about your:
Family medical history
The doctor will also do a physical exam.
The diagnosis is generally made based on physical findings. Examples include:
Cafè-au-lait spot (main sign of NF)—Adults with six or more spots greater than 1.5 cm in diameter are likely to have NF.
Freckling in the armpits, groin, or underneath the breast in women
Multiple soft tumors apparent on the skin or deeper in the body viewed by radiologic testing (scans)
Soft nodules under the skin
Large infiltrating tumors under the skin, which can cause disfigurement and can progress to become malignant peripheral nerve sheath tumors
Pigmented, raised spots on the colored part of the eye
Tests for NF1 may include:
Exam by a doctor familiar with NF1 (eg, neurologist, geneticist, dermatologist)
Eye exam by an ophthalmologist familiar with NF1
Removal of neurofibromas for testing
Other specific tests associated with complications
—a test that uses magnetic waves to make pictures of structures inside the brain
Genetic testing—available for families with a history of NF1 and NF2. Prenatal diagnosis may be possible with
or chorionic villus sampling.
Treatments for both types of NF are aimed at controlling symptoms. NF tumors are not always treated because they:
Are rarely cancerous
May not cause problems
If you have NF, you will need regular exams to check for:
Brown spots on the skin
Bones, including scoliosis
Treatment of NF1
Surgery can help correct some bone abnormalities. Bone surgery may be combined with back braces to treat scoliosis. Surgery can also be used to remove painful or disfiguring tumors. However, tumors may grow back and in larger numbers. In rare cases when tumors become cancerous, treatment may include:
Please be aware that this information is provided to supplement the care
provided by your physician. It is neither intended nor implied to be a
substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER
IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the
advice of your physician or other qualified health provider prior to
starting any new treatment or with any questions you may have regarding a