This genetic disorder is a progressive condition that causes damage to the nervous system and affects the movements of the individual. As the result, the problems range from muscle weakness, heart conditions to difficulty with speech. The main symptom of this condition is ataxia which is the degeneration of the nerve tissue that is responsible for the control of the movement of the arms and the legs. Friedreich ataxia is estimated to affect around 1 in 40,000 individuals in the United States.
Causes
This condition develops as the result of a mutation in the gene FXN which is essential for the production of a protein known as frataxin. This protein is important for the function of the mitochondria which are the energy production areas of the cells. The FXN gene contains a section of DNA known as the GAA trinucleotide repeat which consists of DNA building blocks that appear several times in a row. However, among the individuals affected with this condition, the GAA segment appears to be repeated more than normal. The GAA repeats among the healthy individual is normally 30 repeats, however, among those affected with this condition, the GAA segment is repeated 66 to more than 1,000 times. This abnormally long repeats of GAA trinucleotide affects the normal production of frataxin and as the result, the nerve and muscle cells are unable to function with reduced quantity of frataxin. This disorder is inherited in an autosomal recessive pattern meaning both the copies of the gene in both the cells are defective.
Symptoms
Among most of the affected individuals, the symptoms may develop around the age of 5 and 18 years, although the late onset can also occur. The symptoms include the loss of coordination of the limbs, fatigue, muscle loss, impaired vision, a curvature of the spine, diabetes mellitus, hearing loss, problem with speech and heart conditions. Individuals affected with this condition need the full-time use of a wheelchair as the result of the loss of muscle strength and coordination.
Diagnosis
The diagnosis is based on a thorough clinical examination and with the evaluation of the features that are characteristic of this condition. Friedreich ataxia can be confirmed by the genetic testing that identifies the mutation in the gene that is responsible for causing this disorder.
Treatment
Normally, the treatment for this disorder is to provide relief for the symptoms. These individuals are usually recommended to have a regular medical supervision to prevent any development of complications of various organs of the body such as the heart, muscles, hearing and their vision. The abnormalities of the feet, the curvature of the spine may require surgical or non-surgical interventions. Medications may be used for individuals with heart problems and diabetes mellitus. Corrective devices may be required among those affected with vision and hearing problems. In addition, psychological counseling and speech therapy may also be beneficial.
References
https://ghr.nlm.nih.gov/condition/friedreich-ataxia#inheritance
https://rarediseases.org/rare-diseases/friedreichs-ataxia/
http://brainfoundation.org.au/disorders/friedreichs-ataxia
