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Neurofibromatosis

Description

Neurofibromatosis (NF) occurs in two distinct forms: Type 1 (NF-1, von Recklinghausen's disease) and Type 2 (NF-2).

Causes

NF is a common disorder affecting about 1 in 4000 people. It may be inherited in an autosomal dominant manner, or occur sporadically (not inherited). NF is the consequence of abnormal differentiation and migration of neural cells during the early stages of embryogenesis.

Symptoms

NF-1 is more common and is characterized by multiple (more than 5) tan patches on the skin (café-au-lait spots), freckles in the groin or armpit, nodules within the iris of the eyes, skin neurofibromas (small, rubbery skin lesions), bone defects, and visual disorders. Children with NF-1 are susceptible to neurologic complications including masses in the brain and spinal cord. NF-2 accounts for only 10 percent of all cases and is characterized by bilateral acoustic neuromas (masses around the eight cranial nerve in the brain) which causes hearing loss, facial weakness, headache, or unsteadiness. Café-au-lait spots and skin neurofibromas are much less common. Brain tumors and lens abnormalities (in the eye) may also occur.

Diagnosis

Diagnosis is made by medical history (including symptoms and family history) and physical examination and requires several baseline studies: hearing and vision screening tests, electroencephalogram (EEG), psychologic testing to evaluate possible learning disorders, x-rays of the bones, and head CT (computed tomography) or head MRI (magnetic resonance imaging).

Treatment

There is no specific treatment for NF, and management includes genetic counseling and early detection of treatable conditions or complications. The asymptomatic patient should be re-examined yearly. Symptomatic patients may benefit from surgery treatment of tumors.