Friedreich's Ataxia

Friedreich's ataxia is an inherited disease that causes progressive damage to the nervous system. It can result in muscle weakness, speech difficulties or heart disease. The first symptom is usually difficulty in walking. Many persons with ataxia eventually use wheelchairs.

It is named after the physician Nicholas Friedreich, who first described the condition in the 1860s. Ataxia refers to coordination problems and unsteadiness, and occurs in many different diseases and conditions. In Friedreich’s ataxia, there is degeneration of nerve tissue in the spinal cord and of nerves that control arm and leg movement. The spinal cord becomes thinner and nerve cells lose some of the insulation (myelin) that helps nerves conduct impulses.

Friedreich’s ataxia affects about 1 in every 50,000 people in the United States. Males and females are affected equally. Symptoms usually begin between the ages of 5 and 15 but can appear as early as 18 months or as late as age 30.

Early signs may include foot, involuntary bending of the toes, or foot inversion (turning in). Rapid, involuntary movements of the eyeball are common. Most people with Friedreich’s ataxia develop scoliosis (a curving of the spine to one side), which, if severe, may impair breathing.

Other symptoms include chest pain, shortness of breath, and heart palpitations. Doctors diagnose Friedreich’s ataxia by performing a careful clinical examination, which includes a medical history and a thorough physical examination. Several tests may be performed, including electromyogram (EMG) and genetic testing.

There is currently no effective cure or treatment for Friedreich’s ataxia. However, many of the symptoms and accompanying complications can be treated to help people maintain optimal functioning.

Friedreich’s Ataxia may be inherited as an autosomal recessive trait. Cases in which a family history of the disease has not been found may indicate new genetic changes (mutations) that occur spontaneously. Friedreich’s Ataxia results from mutations of a gene known as "X25, or frataxin, a protein that should normally be present in the nervous system, the heart, and the pancreas. The protein is severely reduced in people with Friedreich’s ataxia.

Studies indicate that patients have abnormally high levels of iron in their heart tissue and that the nervous system, heart, and pancreas may be particularly susceptible to damage from free radicals (produced when the excess iron reacts with oxygen). Nerve and muscle cells also have metabolic needs that may make them particularly vulnerable to free radical damage. The discovery of the genetic mutation that causes Friedreich’s ataxia has added new impetus to research efforts on this disease.

Sources: National Institute of Neurological Disorders and Stroke, National Organization for Rare Disorders