Friedreich ataxia is a rare disease passed down through families (inherited). It affects the muscles and heart.
Friedreich ataxia is caused by a defect in a gene called frataxin (FXN). Changes in this gene cause the body to make too much of a part of DNA called trinucleotide repeat (GAA). Normally, the body contains about 8 to 30 copies of GAA. People with Friedreich ataxia have as many as 1,000 copies. The more copies of GAA a person has, the earlier in life the disease starts and the faster it gets worse.
Friedreich ataxia is an autosomal recessive genetic disorder. This means you must get a copy of the defective gene from both your mother and father.
Symptoms are caused by the wearing away of structures in areas of the brain and spinal cord that control coordination, muscle movement, and other functions. Symptoms most often begin before puberty. Symptoms may include:
Muscle problems lead to changes in the spine. This may result in scoliosis or kyphoscoliosis.
Heart disease most often develops and may lead to heart failure. Heart failure or dysrhythmias that do not respond to treatment may result in death. Diabetes may develop in later stages of the disease.
The following tests may be done:
Blood sugar (glucose) tests may show diabetes or glucose intolerance. An eye exam may show damage to the optic nerve, which most often occurs without symptoms.
Treatment for Friedreich ataxia includes:
Orthopedic devices (braces) may be needed for scoliosis and foot problems. Treating heart disease and diabetes help people live longer and improve their quality of life.
Friedreich ataxia slowly gets worse and causes problems doing everyday activities. Most people need to use a wheelchair within 15 years of the disease's start. The disease may lead to early death.
Complications may include:
Call your health care provider if symptoms of Friedreich ataxia occur, especially if there is a family history of the disorder.
People with a family history of Friedreich ataxia who intend to have children may want to consider genetic screening to determine their risk.
Reviewed By: Neil K. Kaneshiro, MD, MHA, Clinical Professor of Pediatrics, University of Washington School of Medicine, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.