Friedreichs ataxia (FRDA or FA) is an autosomal-recessive genetic disease that causes difficulty walking, a loss of sensation in the arms and legs, and impaired speech that worsens over time. Symptoms generally start between 5 and 20 years of age. Many develop hypertrophic cardiomyopathy and require a mobility aid such as a cane, walker, or wheelchair in their teens. As the disease progresses, some affected people lose their sight and hearing. Other complications may include scoliosis and diabetes mellitus. The condition is caused by mutations in the FXN gene on chromosome 9, which makes a protein called frataxin. In FRDA, cells produce less frataxin. Degeneration of nerve tissue in the spinal cord causes the ataxia; particularly affected are the sensory neurons essential for directing muscle movement of the arms and legs through connections with the cerebellum. The spinal cord becomes thinner, and nerve cells lose some myelin sheath. No effective treatment is known, but several therapies are in trials. FRDA shortens life expectancy due to heart disease, but some people can live into their 60s or older. FRDA affects one in 50,000 people in the United States and is the most common inherited ataxia. Rates are highest in people of Western European descent. The condition is named after German physician Nikolaus Friedreich, who first described it in the 1860s. Symptoms
Symptoms typically start between the ages of 5 and 15, but in late-onset FRDA, they may occur after age 25 years.
Devices
Well-fitted orthoses can promote correct posture, support normal joint alignment, stabilize joints during walking, improve range of motion and gait, reduce spasticity, and prevent foot deformities and scoliosis.Functional electrical stimulation or transcutaneous nerve stimulation devices may alleviate symptoms.As progression of ataxia continues, assistive devices such as a cane, walker, or wheelchair may be required for mobility and independence. A standing frame can help reduce the secondary complications of prolonged use of a wheelchair. Medication and surgery
Cardiac abnormalities can be controlled with ACE inhibitors such as enalapril, ramipril, lisinopril, or trandolapril, sometimes used in conjunction with beta blockers. Affected people who also have symptomatic congestive heart failure may be prescribed eplerenone or digoxin to keep cardiac abnormalities under control.Surgery may correct deformities caused by abnormal muscle tone. Titanium screws and rods inserted in the spine help prevent or slow the progression of scoliosis. Surgery to lengthen the Achilles tendon can improve independence and mobility to alleviate equinus deformity. An automated implantable cardioverter-defibrillator can be implanted after a severe heart failure. Prognosis
The disease evolves differently in different people. In general, those diagnosed at a younger age or with longer GAA triplet expansions tend to have more severe symptoms.Congestive heart failure and abnormal heart rhythms are the leading causes of death, but people with fewer symptoms can live into their 60s or older. Epidemiology
FRDA affects Indo-European populations. It is rare in East Asians, sub-Saharan Africans, and Native Americans. FRDA is the most prevalent inherited ataxia, affecting approximately 1 in 40,000 with European descent. Males and females are affected equally.