Friedreich ataxia is a rare inherited disease that causes progressive damage to the nervous system. It is caused by a defect in the FXN gene that produces the protein frataxin. Frataxin controls important steps in mitochondrial iron metabolism and overall cell iron stability. Research suggests that cells that have a reduced level of frataxin produce energy less effectively, which may lead to a buildup of toxic byproducts.
Symptoms typically appear between ages 5 and 15 years but can begin in adulthood. Damage to the peripheral nerves and the cerebellum (part of the brain that coordinates balance and movement) results in awkward, unsteady movements and impaired muscle coordination (ataxia) that worsens and eventually spreads to the arms and the trunk of the body. Other symptoms include loss of sensory function, speech problems, and vision and hearing loss. Thinking and reasoning abilities are not affected. Many people with Friedreich ataxia develop scoliosis (a curving of the spine to one side), which, if severe, may impair breathing. Some individuals may develop diabetes.
There is currently no effective cure or treatment for Friedreich ataxia. However, many of the symptoms and accompanying complications can be treated to help individuals maintain optimal functioning as long as possible. Diabetes and heart problems can be treated with medications. Orthopedic problems such as foot deformities and scoliosis can be treated with braces or surgery. Rehabilitative therapy (physical, occupational, and vocational) can help individuals become as functionally independent as possible. Hearing impairments can be helped with hearing aids.
Generally, within 10 to 20 years after the appearance of the first symptoms, the person is confined to a wheelchair. In later stages of the disease, individuals may become completely incapacitated. Friedreich ataxia can shorten life expectancy, and heart disease is the most common cause of death. Many individuals with Friedreich ataxia die in early adulthood, but some people with less severe symptoms live into their 60s or older.
NINDS-funded researchers are studying the metabolic functions of mitochondria in individuals with Friedreich ataxia. Ongoing research is aimed at understanding the molecular basis for and mechanisms involved in the inactivation of the gene that provides instructions for frataxin and to develop signs that can indicate the diagnosis or progression of the disease. Researchers are investigating ways to turn off, or "silence," the defective FXN gene. Other research efforts include developing animal models of the disease that closely mimic the gene mutation and developing a protein replacement therapy for the disorder. Information from the National Library of Medicine’s MedlinePlus Friedrich's Ataxia