Neurofibromatosis-1

Definition:

Neurofibromatosis-1 is an inherited disorder characterized by formation of neurofibromas (tumors involving nerve tissue) in the skin, subcutaneous tissue, cranial nerves, and spinal root nerves.

Alternative Names:

NF1; vonRecklinghausen neurofibromatosis

Causes, incidence, and risk factors:

NF1 is an autosomal dominant trait, meaning that if either parent has NF1, their children have a 50% chance of inheriting the disease. NF1 also appears in families with no previous history of the condition, as a result of a new genetic mutation in the particular sperm or egg that created the child. NF1 is caused by abnormalities in one of the genes encoding a protein called neurofibromin.

Neurofibromatosis causes unchecked growth of neurofibromatous tissue in nerves, which can put pressure on affected nerves and cause pain and severe nerve damage. This leads to loss of function in the area served by the nerve. Problems with sensation or movement can occur as a result, depending on the particular nerves affected.

Symptoms:

Symptoms can be extremely varied, depending on the age of the patient and severity of the disease.

Symptoms may include:

Mild impairment of intellectual function, attention deficit disorder
Fracture of the long bones of the leg in early childhood
"Coffee with milk" (cafe-au-lait) spots on the skin
Freckles in the underarm or groin
Convulsions
Pain (associated with affected peripheral nerves)
Blindness
Rubbery tumors of the skin called nodular neurofibromas
Soft tumors which may have a darker color called plexiform neurofibromas

Signs and tests:

The diagnosis of neurofibromatosis is generally made based on physical findings. The cafe-au-lait spot (meaning literally the color of coffee with cream) is the hallmark of neurofibromatosis. Although many normal people have 1 or 2 small cafe-au-lait spots, adults with 6 or more spots greater than 1.5 cm in diameter are likely to have neurofibromatosis.

Other signs include:

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 (plexiform neurofibromas) which can cause disfigurement
Pigmented, raised spots on the colored part (iris) of the eye (Lisch nodules)

Tests may include:

Examination by a doctor familiar with NF1, such as a neurologist, geneticist, or dermatologist
Eye exam by an ophthalmologist familiar with NF1
MRI of the affected site
Removal of neurofibromas of skin lesions
Other specific tests associated with complications
Genetic testing that demonstrates a mutation in the neurofibromin gene

Treatment:

There is no specific treatment for neurofibromatosis. Tumors that cause pain or loss of function are removed on an individual basis. Tumors that have grown rapidly should be removed promptly as they may become malignant. Experimental treatments for severe tumors are under investigation.

Special schooling for those with learning disorders and/or attention-deficit disorder may be required in some cases. Annual eye exams are strongly recommended.

Support Groups:

For more information and resources, contact the http://www.nf.orgNational Neurofibromatosis Foundation.

Expectations (prognosis):

The life expectancy of people with neurofibromatosis is almost normal, barring complications. Although mental impairment is generally mild, NF1 is a known cause of attention deficit hyperactivity disorder in a minority of patients.

With appropriate education and job expectations, people with neurofibromatosis can live a normal life. Some individuals manifest hundreds of tumors on their skin and are subject to stigmatization by society because of the way they look.

Patients with neurofibromatosis have an increased chance of developing severe tumors which, rarely, can shorten life span.

Complications:

Blindness caused by a tumor in an optic nerve (optic glioma)
Malignant transformation of tumors (in approximately 5-10% of affected individuals)
Chance of pheochromocytoma, which causes very high blood pressure
Loss of nerve function in nerves where a neurofibroma's growth has caused prolonged pressure on the nerve
Attention deficit hyperactivity disorder (ADHD)
Cosmetically significant tumors of the face, skin, and other exposed areas
Bowing or breakage of the leg bones with poor healing
Scoliosis or curvature of the spine

Calling your health care provider:

Call your health care provider if you notice cream-with-coffee colored spots on your child's skin or any of the signs listed here, or if you have a family history of neurofibromatosis and would like your child examined. Also, call if anyone in your family has had a neurofibroma removed and you are planning children.

Prevention:

Genetic counseling is recommended for anyone with a family history of neurofibromatosis.

Review Date: 11/7/2002
Reviewed By: David G. Brooks, M.D., Ph.D., Division of Medical Genetics, University of Pennsylvania Medical Center, Philadelphia, PA. Review provided by VeriMed Healthcare Network.

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