December 28, 2012
Dear Mayo Clinic:
What causes neurofibromatosis, and how is it treated? Is it very common? I had not heard of the disease until my niece was diagnosed with neurofibromatosis type 1.
Neurofibromatosis type 1 is a genetic disorder that disrupts cell growth, causing tumors to form. The tumors, called neurofibromas, are associated with nerve tissue. They can arise anywhere in the body. No treatment currently exists that can slow or stop the tumor growth. But close monitoring can help catch complications early, so they can be treated as soon as possible.
Neurofibromatosis affects about 1 in 3,000 people. About 50 percent of those affected have a family history of the disease. In the other 50 percent, the gene mutation that causes neurofibromatosis develops spontaneously. In people who have neurofibromatosis, the likelihood that they will pass it on to their children is 50 percent.
In children, symptoms of neurofibromatosis usually include flat, light-brown spots on the skin, called café au lait macules, and freckling in the groin or armpits. Eventually soft bumps that are neurofibromas may develop under the skin. Neurofibromatosis may result in bone problems, such as scoliosis or bowing of bones in the legs. Children may have developmental delays, low muscle tone, a larger than average head size, short stature and learning problems. In some people, neurofibromatosis can result in eye problems. If a tumor directly affects a nerve, the disease may cause chronic pain.
Fortunately, most people with neurofibromatosis have cases that are mild and cause few symptoms or complications. Many adults who have the disease are not aware of it.
Treatment options for neurofibromatosis are limited. Because the development and growth of the tumors cannot be stopped, it is important for people with this disease to receive ongoing medical care from a team of specialists familiar with neurofibromatosis. Clinics for neurofibromatosis are usually coordinated by a geneticist or neurologist. With careful monitoring, such a team often can identify medical problems that arise because of neurofibromatosis early, and start treatment quickly.
If a tumor begins to damage tissue or compress nerves, surgery to take it out may help relieve symptoms. In advanced tumors this can be complicated, and the procedure to remove a tumor can cause lasting nerve damage. The tumor also may grow back. For these reasons, the pros and cons of using surgery to treat neurofibromatosis need to be considered carefully.
Most neurofibromatosis tumors are not cancerous, but some of the tumors associated with neurofibromatosis are cancers. These uncommon malignant tumors are treated with standard cancer therapies such as surgery and chemotherapy and radiation therapies.
Research to improve neurofibromatosis treatment is ongoing. Several drugs are being studied in clinical trials that may slow the development of the tumors. Some of these drugs block the formation of blood vessels. That may help because tumors need more blood than normal tissues. If a tumor does not receive enough blood, it cannot grow as quickly as usual.
Because neurofibromatosis can affect many areas of the body and can be difficult to treat, it is important to seek care from a health care organization that has a neurofibromatosis clinic. That clinic should be staffed with experts in the disease, as well as specialists from a variety of other medical and surgical areas who can help with all aspects of diagnosis and treatment, as needed.
— Dusica Babovic-Vuksanovic, M.D., Medical Genetics, Mayo Clinic, Rochester, Minn.