Although rare diseases tend to be quirky conditions with odd signs or weird combinations of symptoms, many of them have one thing in common: It often takes years to diagnose them. One example is a rare inherited disease known as Friedreich’s ataxia (FA).
This condition causes neurological damage and problems with movement. According to the National Institute of Neurological Disorders and Stroke (NINDS), it usually develops in childhood and worsens with age.
The Washington Post profiled a teenager who struggled for years with increasing difficulties walking and a probable diagnosis of cerebral palsy before a doctor determined he suffered from FA. The condition is a rare inherited malady that takes its name from Nicholaus Friedreich, the German physician who described it in the 1860s.
The cause of FA is a mutation in a gene known as FXN. Since the disease is a recessive disorder, someone who develops it must inherit a defective copy of the gene from each parent.
The illness strikes both boys and girls. It develops in around 1 of every 50,000 people living in the United States.
Signs and Symptoms
The typical age range when symptoms first appear is between ages 5 and 15. However, some adults develop the condition, sometimes in their 70s. The initial symptom is usually difficulty walking, or gait ataxia.
As the problem worsens, it spreads gradually to the patient’s arms and trunk. Sometimes there is a loss of sensation in the extremities that can progress to other parts of the body.
Additional signs include scoliosis and loss of tendon reflexes. A slowness and slurring of speech called dysarthria appears and can worsen over time. The later stages of Friedreich’s ataxia are sometimes marked by vision and hearing loss.
Other symptoms FA patients experience are chest pain, heart palpitations, and shortness of breath linked to several forms of heart disease that can accompany the illness. Abnormalities in the heart’s rhythm are also common.
Fatigue is common among FA sufferers. Around 20 percent develop a carbohydrate intolerance. One in 10 will develop diabetes.
The typical progression of this rare condition puts a patient in a wheelchair 10 to 20 years after its first signs make an appearance. The most common cause of death for FA patients, who can experience a shortened life expectancy, is heart disease. Patients with less-severe FA manifestations sometimes live into the senior years, however.
Diagnosis and Treatment
In addition to a standard physical exam, medical history, and genetic testing, doctors have at their disposal a number of diagnostic tools to help identify FA. They include:
Electromyogram (EMG): measures electrical activity in muscle cells
Nerve conduction studies: measure the speed with which the patient’s nerves transmit impulses
Echocardiogram: Shows the position and motion of an individual’s heart muscle
Electrocardiogram (ECG): Displays the heart’s electrical activity and beat pattern
Imaging (MRI or CT scan): Images are useful in ruling out other neurological problems
Blood tests: Can detect higher-than-normal glucose levels and vitamin E levels.
Like many degenerative neurological conditions, Friedreich’s ataxia has no cure or effective treatment. Doctors instead strive to treat the complications of the illness to help patients function well for as long as possible.
They use medication to treat diabetes and heart problems that develop. Braces and surgery can help orthopedic issues. Patients often undergo physical therapy to maintain the use of their limbs.
Healthcare professionals consider genetic testing a necessity to render an accurate FA diagnosis. They can provide patients and their families with information on how to take advantage of counseling and support groups.
NINDS is the federal agency with the main oversight for sponsoring FA research. Researchers believe they have developed an initial understanding of the genetics behind this rare disease. Work is already in progress to find effective ways to treat and prevent Friedreich’s ataxia.