Friedreich's Ataxia Fact Sheet

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Ataxia de Friedreich

Table of Contents (click to jump to sections)

What is Friedreich's ataxia?

What are the signs and symptoms?

How is Friedreich's ataxia diagnosed?

How is Friedreich's ataxia inherited?

Can Friedreich's ataxia be cured or treated?

What services are useful to Friedreich's ataxia patients and

their families?

What research is being done?

Where can I get more information?

What is Friedreich's ataxia?

Friedreich's ataxia (also called FA or FRDA) is a rare inherited disease that causes nervous system damage and movement

problems. It usually begins in childhood and leads to impaired muscle coordination (ataxia) that worsens over time. The disorder

is named after Nicholaus Friedreich, a German doctor who first described the condition in the 1860s.

In Friedreich’s ataxia the spinal cord and peripheral nerves degenerate, becoming thinner. The cerebellum, part of the brain that

coordinates balance and movement, also degenerates to a lesser extent. This damage results in awkward, unsteady movements

and impaired sensory functions. The disorder also causes problems in the heart and spine, and some people with the condition

develop diabetes. The disorder does not affect thinking and reasoning abilities (cognitive functions).

Friedreich’s ataxia is caused by a defect (mutation) in a gene labeled FXN. The disorder is recessive, meaning it occurs only in

someone who inherits two defective copies of the gene, one from each parent. Although rare, Friedreich’s ataxia is the most

common form of hereditary ataxia, affecting about 1 in every 50,000 people in the United States. Both male and female children

can inherit the disorder.

What are the signs and symptoms?

Symptoms typically begin between the ages of 5 and 15 years, although they sometimes appear in adulthood and on rare

occasions as late as age 75. The first symptom to appear is usually gait ataxia, or difficulty walking. The ataxia gradually

worsens and slowly spreads to the arms and the trunk. There is often loss of sensation in the extremities, which may spread to

other parts of the body. Other features include loss of tendon reflexes, especially in the knees and ankles. Most people with

Friedreich's ataxia develop scoliosis (a curving of the spine to one side), which often requires surgical intervention for treatment.

Dysarthria (slowness and slurring of speech) develops and can get progressively worse. Many individuals with later stages of

Friedreich’s ataxia develop hearing and vision loss.

Other symptoms that may occur include chest pain, shortness of breath, and heart palpitations. These symptoms are the result

of various forms of heart disease that often accompany Friedreich's ataxia, such as hypertrophic cardiomyopathy (enlargement

of the heart), myocardial fibrosis (formation of fiber-like material in the muscles of the heart), and cardiac failure. Heart rhythm

abnormalities such as tachycardia (fast heart rate) and heart block (impaired conduction of cardiac impulses within the heart) are

also common.

About 20 percent of people with Friedreich's ataxia develop carbohydrate intolerance and 10 percent develop diabetes. Most

individuals with Friedreich’s ataxia tire very easily and find that they require more rest and take a longer time to recover from

common illnesses such as colds and flu.

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The rate of progression varies from person to person. Generally, within 10 to 20 years after the appearance of the first

symptoms, the person is confined to a wheelchair, and in later stages of the disease individuals may become completely

incapacitated.

Friedreich's ataxia can shorten life expectancy, and heart disease is the most common cause of death. However, some people

with less severe features of Friedreich's ataxia live into their sixties, seventies, or older.

How is Friedreich's ataxia diagnosed?

A diagnosis of Friedreich's ataxia requires a careful clinical examination, which includes a medical history and a thorough physical

exam, in particular looking for balance difficulty, loss of proprioception (joint sensation), absence of reflexes, and signs of

neurological problems. Genetic testing now provides a conclusive diagnosis. Other tests that may aid in the diagnosis or

management of the disorder include:

electromyogram (EMG), which measures the electrical activity of muscle cells,

nerve conduction studies, which measure the speed with which nerves transmit impulses,

electrocardiogram (ECG), which gives a graphic presentation of the electrical activity or beat pattern of the heart,

echocardiogram, which records the position and motion of the heart muscle,

blood tests to check for elevated glucose levels and vitamin E levels, and

magnetic resonance imaging (MRI) or computed tomography (CT) scans, tests which provide brain and spinal cord

images that are useful for ruling out other neurological conditions.

How is Friedreich's ataxia inherited?

Friedreich's ataxia is an autosomal recessive disease, meaning individuals only develop symptoms if they inherit two copies of the

defective FXN gene, one from their father and one from their mother. A person who has only one abnormal copy of the gene is

called a carrier. A carrier will not develop the disease but could pass the gene mutation on to his or her children. If both parents

are carriers, their children will have a 1 in 4 chance of having the disease and a 1 in 2 chance of inheriting one abnormal gene

that they, in turn, could pass on to their children. About one in 90 Americans of European ancestry carries an abnormal FXN

gene.

In 1996, an international research team identified the Friedreich’s ataxia gene on chromosome 9. The FXN gene codes for

production of a protein called "frataxin." In the normal version of the gene, a sequence of DNA (labeled “GAA”) is repeated

between 7 and 22 times. In the defective FXN gene, the repeat occurs over and over again—hundreds, even up to a thousand

times.

This abnormal pattern, called a triplet repeat expansion, has been implicated as the cause of several dominantly inherited

diseases, but Friedreich's ataxia is the only known recessive genetic disorder caused by the problem. Almost all people with

Friedreich's ataxia have two copies of this mutant form of FXN, but it is not found in all cases of the disease. About two percent

of affected individuals have other defects in the FXN gene that are responsible for causing the disease.

The triplet repeat expansion greatly disrupts the normal production of frataxin. Frataxin is found in the energy-producing parts of

the cell called mitochondria. Research suggests that without a normal level of frataxin, certain cells in the body (especially

peripheral nerve, spinal cord, brain and heart muscle cells) cannot effectively produce energy and have been hypothesized to

have a buildup of toxic byproducts leading to what is called “oxidative stress.” It also may lead to increased levels of iron in the

mitochondria. When the excess iron reacts with oxygen, free radicals can be produced. Although free radicals are essential

molecules in the body's metabolism, they can also destroy cells and harm the body. Research continues on this subject (see

section on “What research is being done?”).

Can Friedreich's ataxia be cured or treated?

As with many degenerative diseases of the nervous system, there is currently no cure or effective treatment for Friedreich's

ataxia. However, many of the symptoms and accompanying complications can be treated to help individuals maintain optimal

functioning as long as possible. Doctors can prescribe treatments for diabetes, if present; some of the heart problems can be

treated with medication as well. Orthopedic problems such as foot deformities and scoliosis can be corrected with braces or

surgery. Physical therapy may prolong use of the arms and legs. Advances in understanding the genetics of Friedreich's ataxia

are leading to breakthroughs in treatment. Research has moved forward to the point where clinical trials of proposed treatments

are presently occurring for Friedreich’s ataxia.

What services are useful to Friedreich's ataxia patients and their families?

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Genetic testing is essential for proper clinical diagnosis, and can aid in prenatal diagnosis and determining a person’s carrier

status. Genetic counselors can help explain how Friedreich's ataxia is inherited. Psychological counseling and support groups for

people with genetic diseases may also help affected individuals and their families cope with the disease.

A primary care physician can screen people for complications such as heart disease, diabetes and scoliosis, and can refer

individuals to specialists such as cardiologists, physical therapists, and speech therapists to help deal with some of the other

associated problems.

Support and information for families is also available through a number of private organizations. These groups can offer ways to

network and communicate with others affected by Friedreich’s ataxia. They can also provide access to patient registries, clinical

trials information, and other useful resources.

What research is being done?

Within the Federal government the National Institute of Neurological Disorders and Stroke (NINDS), a component of the National

Institutes of Health (NIH), has primary responsibility for sponsoring research on neurological disorders. As part of this mission,

the NINDS conducts research on Friedreich's ataxia and other forms of inherited ataxias at its facilities at the NIH and supports

additional studies at medical centers throughout the United States. Several nonprofit organizations also provide substantial

support research (see the section on "Where can I get more information?").

Researchers are optimistic that they have begun to understand the causes of the disease, and work has begun to develop

effective treatments and prevention strategies for Friedreich's ataxia. Scientists have been able to create various models of the

disease in yeast and mice which have facilitated understanding the cause of the disease and are now being used for drug

discovery and the development of novel treatments.

Studies have revealed that frataxin is an important mitochondrial protein for proper function of several organs. Yet in people with

the disease, the amount of frataxin in affected cells is severely reduced. It is believed that the loss of frataxin makes the nervous

system, heart, and pancreas particularly susceptible to damage from free radicals (produced when the excess iron reacts with

oxygen). Once certain cells in these tissues are destroyed by free radicals they cannot be replaced. Nerve and muscle cells also

have metabolic needs that may make them particularly vulnerable to this damage. Free radicals have been implicated in other

degenerative diseases such as Parkinson's and Alzheimer's diseases.

Based upon this information, scientists and physicians have tried to reduce the levels of free radicals, also called oxidants, using

treatment with “antioxidants.” Initial clinical studies in Europe suggested that antioxidants like coenzyme Q10, vitamin E, and

idebenone may offer individuals some limited benefit. However, recent clinical trials in the United States and Europe have not

revealed effectiveness of idebenone in people with Friedreich’s ataxia, but more powerful modified forms of this agent and other

antioxidants are in trials at this time. There is also a clinical trial to examine the efficacy of selectively removing excess iron from

the mitochondria.

Scientists also are exploring ways to increase frataxin levels through drug treatments, genetic engineering and protein delivery

systems. Several compounds that are directed at increasing levels of frataxin may be brought to clinical trials in the near future.

To check for current trials, visit http://www.clinicaltrials.gov. Additional information is available from the groups listed in the

following section.

Armed with what they currently know about frataxin and Friedreich’s ataxia, scientists are working to better define fraxatin’s role,

clarify how defects in iron metabolism may be involved in the disease process, and explore new therapeutic approaches for

therapy.

Where can I get more information?

For more information on neurological disorders or research programs funded by the National Institute of Neurological Disorders

and Stroke, contact the Institute's Brain Resources and Information Network (BRAIN) at:

BRAIN

P.O. Box 5801

Bethesda, MD 20824

(800) 352-9424

http://www.ninds.nih.gov

Information also is available from the following organizations:

Friedreich's Ataxia Research Alliance (FARA)

P.O. Box 1537

Springfield, VA 22151

fara@CureFA.org

http://www.CureFA.org

Tel: (703) 426-1576

Genetic Alliance

4301 Connecticut Avenue, N.W.

Suite 404

Washington, DC 20008-2369

info@geneticalliance.org

http://www.geneticalliance.org

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Fax: (703) 425-0643 Tel: 202-966-5557 800 336-GENE (4363)

Fax: 202-966-8553

Muscular Dystrophy Association

3300 East Sunrise Drive

Tucson, AZ 85718-3208

mda@mdausa.org

http://www.mda.org

Tel: 520-529-2000 800-572-1717

Fax: 520-529-5300

National Ataxia Foundation (NAF)

2600 Fernbrook Lane North

Suite 119

Minneapolis, MN 55447-4752

naf@ataxia.org

http://www.ataxia.org

Tel: 763-553-0020

Fax: 763-553-0167

National Organization for Rare Disorders (NORD)

55 Kenosia Avenue

Danbury, CT 06810

orphan@rarediseases.org

http://www.rarediseases.org

Tel: 203-744-0100 Voice Mail 800-999-NORD (6673)

Fax: 203-798-2291

"Friedreich's Ataxia Fact Sheet," NINDS. Publication date September 2010.

NIH Publication No. 10-87

Back to Friedreich's Ataxia Information Page

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Ataxia de Friedreich

Prepared by:

Office of Communications and Public Liaison

National Institute of Neurological Disorders and Stroke

National Institutes of Health

Bethesda, MD 20892

NINDS health-related material is provided for information purposes only and does not necessarily represent endorsement by or

an official position of the National Institute of Neurological Disorders and Stroke or any other Federal agency. Advice on the

treatment or care of an individual patient should be obtained through consultation with a physician who has examined that patient

or is familiar with that patient's medical history.

All NINDS-prepared information is in the public domain and may be freely copied. Credit to the NINDS or the NIH is appreciated.

Last updated August 16, 2011

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