Friedreich’s Ataxia
Definition
Friedreich’s ataxia is a very rare inherited disease that causes progressive damage to the nervous system. Ataxia refers to coordination problems and unsteadiness. Friedreich’s ataxia causes degeneration of neurons in the spinal cord that control movement, as well as the sensory nerves that assist coordination. In later stages, additional cell injury can develop in the heart and pancreas.
The Nervous System
Causes
The cause of Friedreich’s ataxia is a mutation in the frataxin gene, which is located on chromosome 9q13. To develop this disease, a person must inherit a copy of the defective gene from each parent. However, most cases are sporadic, without family history of the disorder.
Symptoms
Symptoms may vary. The following list describes the most common symptoms:
Early Symptoms
- Age of onset: under the age of 25, usually in the early teenage years
- Progressive leg weakness (eg, difficulty walking)
- Ataxia—incoordination and imbalance affecting limbs and gait
- Impaired sensation—especially "position sense" in the feet
- Loss of tendon reflexes in the legs
- Heart failure and diabetes develop as the disease progresses
Late Symptoms
- Difficulty speaking and swallowing—decreased coordination of the tongue
- Loss of tendon reflexes in all limbs
- Atrophy of muscles
- Scoliosis —curving of spine (affects 85% of people with this condition)
- Foot deformities
- Foot ulcers
- Confined to a wheelchair (by age 45, occurs in 95% of those affected)
- Hearing loss and or vision loss (over 10% of those affected)
- Eye movement abnormalities
- Movement disorders (eg, tremor, dystonia, chorea)
Diagnosis
Your doctor will ask about your symptoms, including medical history, family history, and medications. Your doctor will also perform a physical exam. If this disorder is suspected, you may also see a neurologist, a doctor who specializes in the nervous system.
Tests may include:
- EMG and nerve conduction studies —a test to assess the function of the muscles and nerves
- Computerized tomography —a test that uses a computer to make cross-sectional images of the head
- MRI scan —a test that uses magnetic waves to make pictures of structures inside the brain and spinal cord
- Electrocardiogram and 24-hour holter monitoring —a test that assesses the electrical activity of the heart
- Echocardiogram —a test that uses high-frequency sound waves (ultrasound) to examine the size, shape, and motion of the heart
- Genetic testing for the frataxin gene
- Blood (diabetic testing) and urine tests
- Sural nerve biopsy
Treatment
There is no known cure for this condition.
Long-term management is aimed at maximizing function and controlling symptoms:
- Physical therapy and rehabilitation to cope with muscle weakness
- Use of orthotics (devices that go in your shoes) to provide stability and to help with weakness
- Surgery for correcting foot abnormalities and scoliosis
- Periodic testing for associated conditions of diabetes and cardiomyopathy
As the exact role of the protein frataxin is clarified, treatments may emerge. Studies are ongoing to assess the role of antioxidants, coenzyme Q 10 , and vitamin E .
RESOURCES:
Friedreich’s Ataxia Research Alliance
http://www.faresearchalliance.org
Genetic Alliance
http://www.geneticalliance.org
National Ataxia Foundation
http://www.ataxia.org
CANADIAN RESOURCES:
International Network of Ataxia Friends
http://internaf.org/
Muscular Dystrophy Canada
http://www.muscle.ca/
References:
Bradley WG, Daroff RB. Neurology in Clinical Practice . Philadelphia, PA: Butterworth Heinemann; 2004.
Friedreich’s ataxia. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed/what.php . Accessed May 12, 2008
Friedreich’s ataxia. National Library of Medicine website. Available at: http://www.nlm.nih.gov/medlineplus/ency/article/001411.htm . Accessed September 12, 2005.
Friedreich’s ataxia fact sheet. National Institute of Neurological Disorders and Stroke website. Available at: http://www.ninds.nih.gov/disorders/friedreichs_ataxia/detail_friedreichs_ataxia.htm . Accessed September 12, 2005.
Nashatizadeh, Muhammad M. Ataxia. In: Gilman S, ed. MedLink Neurology. San Diego, CA: MedLink Corporation. MedLink website. Available at: http://www.medlink.com . Accessed May 12, 2008.
Last reviewed January 2009 by J. Thomas Megerian, MD, PhD, FAAP
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
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