Friedreich's Ataxia (FA or FRDA) is a debilitating and life shortening degenerative neuromuscular disease. It affects about 1 in 50,000 people in the United States. FA is an inherited single gene disorder which is caused by mutations or DNA changes in the FXN gene. It is an autosomal recessive trait meaning that both parents of a child must carry the gene for the child to have FA. About 1 in 100 people are carriers and most do not exhibit symptoms. Each carrier parent has one mutated and one regular gene in the FXA gene complex. Because only one of the mother’s genes and one of the father’s are passed down to the child, there is a 25% chance that the child will have FA. The gene mutation limits the production of fraxtine which is an important protein in the mitochondria (energy producing area of the cell). Fraxtine helps in the balance of iron as well as formation of iron-sulfur clusters which are essential in energy production. In people with FA, certain neurons will degenerate and which contributes to the symptoms of the disease.
Most individuals have their first symptoms in between the ages of 5 and 18. Late onset FA is less common occurring in only less than 25% of diagnosed individuals. There are a multiple signs and symptoms of FA including ataxia (loss of coordination) in arms and/or legs, fatigue (extreme tiredness), vision impairment, hearing loss, slurred speech, abnormal curvature of the spine (scoliosis), diabetes mellitus, as well as many others. About 75% of affected individuals have heart conditions such as HCM or arrhythmias. FA patients usually develop cardiomyopathies before the age of 40. Symptoms do not occur in all affected individuals. Mental capabilities remain fairly intact. Most young people with FA may require canes, walkers, or wheelchairs by their teens or early 20s.
The process for diagnosis may include, a medical history, a complete physical exam in order to look for balance difficulty, absence of reflexes as well as signs of neurological problems. Due to advances in research, it is now possible to receive a conclusive diagnosis with genetic testing. An echocardiogram, electrocardiogram, blood tests, as well as MRIs or CT scans may be required.
There are currently no cures for FA however, symptom management is required. Many of the symptoms accompanying FA can be treated to ensure optimal functioning for as long as possible. Doctors can prescribe treatment for diabetes when present as well as recommend physical therapy which may prolong the use of the extremities (arms and legs).
Figure 1: Image showing the comparison of 3 patients with FA and 3 healthy patients. In the 3 patients with FA, iron accumulation is present.
“What Is Friedreich's Ataxia?” FARA, www.curefa.org/whatis.