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Neurofibromatosis-1
Definition
Neurofibromatosis-1 is an inherited disorder in which nerve tissue tumors (neurofibromas) form in the:
- Bottom layer of skin (subcutaneous tissue)
- Nerves from the brain (cranial nerves) and spinal cord (spinal root nerves)
- Skin
Alternative Names
NF1; Von Recklinghausen neurofibromatosis
Causes
NF1 is an inherited disease. If either parent has NF1, each of their children has a 50% chance of having the disease.
NF1 also appears in families with no history of the condition. In these cases, it is caused by a new gene change (mutation) in the sperm or egg. NF1 is caused by problems with a gene for a protein called neurofibromin.
Symptoms
Neurofibromatosis causes tissue along the nerves to grow uncontrollably. This growth can put pressure on affected nerves. It can cause pain, severe nerve damage, and loss of function in the area served by the nerve. Problems with feeling or movement can occur, depending on which nerves are affected.
The condition can be very different from person to person, even among people in the same family who have the NF1 gene.
"Coffee-with-milk" (café-au-lait) spots are the hallmark symptom of neurofibromatosis. Many healthy people have 1 or 2 small café-au-lait spots. However, adults who have six or more spots that are bigger than 1.5 cm in diameter (0.5 cm in children) are likely to have neurofibromatosis. In most people with the condition, these spots may be the only symptom.
Other symptoms may include:
- Blindness
- Convulsions
- Freckles in the underarm or groin
- Large, soft tumors called plexiform neurofibromas, which may have a dark color and may spread under the surface of the skin
- Pain (from affected nerves)
- Small, rubbery tumors of the skin called nodular neurofibromas
Exams and Tests
A doctor who treats NF1, such as a neurologist, geneticist, dermatologist, or developmental pediatrician will diagnose this condition. The diagnosis will usually be made based on the unique symptoms and signs of neurofibromatosis.
Signs include:
- Colored, raised spots (Lisch nodules) on the colored part (iris) of the eye
- Fracture of the long bones of the leg in early childhood
- Freckling in the armpits, groin, or underneath the breast in women
- Large tumors under the skin (plexiform neurofibromas), which can affect the appearance and put pressure on nearby nerves or organs
- Many soft tumors on the skin or deeper in the body
- Mild cognitive impairment, attention deficit hyperactivity disorder (ADHD), learning disorders
Tests may include:
- Eye exam by an ophthalmologist familiar with NF1
- Genetic tests to find a change (mutation) in the neurofibromin gene
- MRI of the affected site
- Other tests for complications
Treatment
There is no specific treatment for neurofibromatosis. Tumors that cause pain or loss of function may be removed. Tumors that have grown quickly should be removed promptly as they may become cancerous (malignant). Experimental treatments for severe tumors are under investigation.
Some children with learning disorders may need special schooling.
Support Groups
For more information and resources, contact the National Neurofibromatosis Foundation.
Outlook (Prognosis)
If there are no complications, the life expectancy of people with neurofibromatosis is almost normal. With the right education, people with neurofibromatosis can live a normal life.
Although mental impairment is generally mild, NF1 is a known cause of attention deficit hyperactivity disorder. Learning disabilities are a common problem.
Some people are treated differently because they have hundreds of tumors on their skin.
Patients with neurofibromatosis have an increased chance of developing severe tumors. In rare cases, these can shorten a person's lifespan.
Possible Complications
- Attention deficit hyperactivity disorder (ADHD)
- Blindness caused by a tumor in an optic nerve (optic glioma)
- Break in the leg bones that does not heal well
- Cancerous tumors
- Loss of function in nerves that a neurofibroma has put pressure on over the long term
- Pheochromocytoma, which causes very high blood pressure
- Regrowth of NF tumors
- Scoliosis, or curvature of the spine
- Tumors of the face, skin, and other exposed areas
When to Contact a Medical Professional
Call your health care provider if:
- You notice coffee-with-milk colored spots on your child's skin or any other symptoms of this condition.
- You have a family history of neurofibromatosis and are planning to have children, or you would like to have your child examined.
Prevention
Genetic counseling is recommended for anyone with a family history of neurofibromatosis.
Annual eye exams are strongly recommended.
References
Ferner RE. Neurofibromatosis 1 and neurofibromatosis 2: a twenty first century perspective. Lancet Neurol. 2007;6:340-351.
Friedman JM. Neurofibromatosis 1. In: Pagon RA, bird TD, Dolan CR, et al., eds. GeneReviews. University of Washington, Seattle; 1993.
Sahin M. Neurocutaneous Syndromes. In: Kliegman RM, Stanton BF, St. Geme J, Schor N, Behrman RE, eds. Nelston Textbook of Pediatrics. 19th ed. Philadelphia, Pa: Saunders Elsevier; 2011: chap 589.
Reviewed By: Chad Haldeman-Englert, MD, FACMG, Wake Forest School of Medicine, Department of Pediatrics, Section on Medical Genetics, Winston-Salem, NC. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M. Health Solutions, Ebix, Inc.
