NF1, also called von Recklinghausen NF or peripheral NF, is characterized by multiple café au lait spots (patches of tan or light brown skin) and neurofibromas (soft, fleshy growths) on or under the skin. Enlargement and deformation of bones and curvature of the spine (scoliosis) may also occur. Occasionally, tumors may develop in the brain, on cranial nerves, or on the spinal cord. About 50% to 75% of people with NF1 also have learning disabilities.
NF2, also called bilateral acoustic NF (BAN), is much less common than NF1 and is characterized by multiple tumors on the cranial and spinal nerves. Tumors that affect both of the auditory nerves and hearing loss beginning in the teens or early twenties are generally the first symptom of NF2.
What Causes Neurofibromatosis?
Neurofibromatosis is often inherited (passed on by family members through our genes), but about 50% of people newly diagnosed with the disorder have no family history of the condition, which can arise spontaneously through a mutation (change) in the genes. Once this change has taken place, the mutant gene can be passed on to future generations.
What Are the Symptoms of Neurofibromatosis?
The following symptoms appear in people with NF1:
- Several (usually 6 or more) café au lait spots
- Multiple freckles in the armpit or groin area
- Tiny growths in the iris (colored area) of the eye; these are called Lisch nodules and usually do not affect eyesight.
- Neurofibromas that occur on or under the skin, sometimes even deep within the body; these are benign (harmless) tumors; however, in rare cases, they can turn malignant or cancerous.
- Bone deformities, including a twisted spine (scoliosis) or bowed legs
- Tumors along the optic nerve, which may cause eyesight problems
- Nerve-related pain
People with NF2 often display the following symptoms:
- Loss of hearing
- Weakness of the muscles of the face
- Dizziness
- Poor balance
- Uncoordinated walking
- Cataracts (cloudy areas on the lens of the eye) that develop at an unusually early age
People with schwannomatosis may have the following symptoms:
- Pain from the enlarging tumors
- Numbness and tingling of the fingers or toes
- Weakness in the fingers and toes
How Is Neurofibromatosis Diagnosed?
Neurofibromatosis is diagnosed using a number of tests, including:
- Physical examination
- Medical history
- Family history
- X-rays
- Computerized tomography (CT) scans
- Magnetic resonance imaging (MRI)
- Biopsy of neurofibromas
- Eye tests
- Tests for particular symptoms, such as hearing or balance tests
- Genetic testing
To receive a diagnosis of NF1, you must have 2 of the following symptoms:
- Six or more café au lait spots that are 1.5 cm or larger in post-pubertal individuals or 0.5 cm or larger in pre-pubertal individuals
- Two or more neurofibromas (tumor that develops from the cells and tissues that cover nerves) of any type or one or more plexiform neurofibroma (nerve that has become thick and misshapen due to the abnormal growth of cells and tissues that cover the nerve)
- Freckling in the armpit or groin
- Optic glioma (tumor of the optic pathway)
- Two or more Lisch nodules
- A distinctive bony lesion, dysplasia of the sphenoid bone or dysplasia or thinning of long bone cortex
- A first-degree relative with NF1
To be diagnosed with NF2, you must have:
- Bilateral (on both sides) vestibular schwannomas, also known as acoustic neuromas; these are benign tumors that develop from the balance and hearing nerves supplying the inner ear.
or
- Family history of NF2 (first degree family relative) plus unilateral (on one side) vestibular schwannomas or any two of the following health conditions:
- Glioma (cancer of the brain that begins in glial cells, which are those that surround and support nerve cells)
- Meningioma (tumor that occurs in the meninges, the membranes that cover and protect the brain and spinal cord)
- Any neurofibromas
- Schwannoma
- Juvenile cataracts
No comments:
Post a Comment