Friedreich ataxia is a relatively rare inherited disease of the nervous system characterised by the gradual loss of coordination. The affected person has increasing difficulty with coordination, leading to an unsteady gait and slurred speech. To the casual observer, a person with Friedreich ataxia may seem to be drunk.
The onset of symptoms usually occurs on average between 10 and 15 years of age, but can be as early as 4 years or as late as middle age. Most ultimately require the use of a wheelchair full-time, on average 15 years after symptom onset. Life span may also be reduced. However, it is impossible to predict how fast the disease will progress – some people will progress faster than others.
Friedreich ataxia can cause abnormalities of the heart muscle and this can trigger palpitations. About 10 per cent of people with Friedreich ataxia develop diabetes. Friedreich ataxia accounts for around half of all cases of hereditary ataxia (unsteady gait).
There is currently no cure for Friedreich ataxia, but some of the symptoms can be managed with medication and physical therapy.
Degeneration of neurones
The part of the brain responsible for motor skills, such as voluntary movement, coordination and balance, is the cerebellum, which is located low in the brain behind the brain stem.
Nerve cells are called neurones, and each neurone has three basic parts, being the cell body (soma), a long ‘tail’ (axon) and a branching of tiny projections (dendrites) that connect to other neurones. The symptoms of Friedreich ataxia are caused by the gradual deterioration of the axons in the cerebellum and spinal cord, which prevents electrical messages from passing smoothly between neurones and on to the muscles.
Causes of Friedreich ataxia
Friedreich ataxia is caused by faults in a gene called FXN
, which is located on chromosome 9. This defective gene interferes with the production of a particular protein called frataxin. Genetic counselling is recommended for parents who already have one child with the disease, as well as relatives of people with the condition.
Friedreich ataxia is autosomal recessive, meaning both parents have one faulty gene, but don’t exhibit any symptoms themselves, since they have a second healthy copy. The children of parents who are both healthy carriers of a single faulty FXN gene each have a 25 per cent chance of being affected by Friedreich ataxia and a 50 per cent chance of being carriers like their parents.
Diagnosis of Friedreich ataxia
Friedreich ataxia is diagnosed using a number of tests including:
- medical history
- physical examination
- electrical nerve conduction tests
- echocardiogram (ultrasound of the heart)
- magnetic resonance imaging (MRI) scan
- genetic testing – the method for definitive diagnosis of Friedreich ataxia.
Symptoms of Friedreich ataxia
Friedreich ataxia progresses slowly. At first, the person’s lack of coordination may be mistaken for clumsiness.
- lack of physical coordination
- loss of balance
- unsteadiness on the feet
- the need to maintain balance by positioning the feet widely apart
- unsteadiness is worsened if the person can’t see (such as in the dark)
- muscle weakness as the condition gets worse
- walking abnormalities
- lack of tendon reflexes in the legs
- jerky movements and lack of coordination ultimately involving the arms, legs and body
- speech difficulties, such as slurring
- swallowing problems and an associated risk of choking
- increased susceptibility to respiratory infections
- other abnormal changes in skin sensation, such as reduced ability to feel temperature, pressure or pain
- spine curvatures, such as scoliosis (abnormal sideways curves).
Complications of Friedreich ataxia
Two out of three people with Friedreich ataxia will have associated heart problems called cardiomyopathy. The heart muscle fibres degenerate and, ultimately, impair the heart’s functioning. This can cause a range of problems, including palpitations and congestive heart failure.
Some of the other complications include:
- diabetes mellitus
- vision problems, which rarely include blindness
- hearing difficulties, including deafness. Many people with Friedreich ataxia have normal hearing in a quiet environment, but significant problems hearing in a noisy environment.
Treatment for Friedreich ataxia
There is no cure for Friedreich ataxia. Treatment aims to ease some of the symptoms and may include:
- exercise, such as swimming
- avoiding bed rest unless absolutely necessary (being immobile seems to exacerbate walking problems)
- maintaining a healthy weight for your height
- orthopaedic aids
- adaptations to the home, such as wheelchair access ramps
- medication to reduce muscle tremors and spasms
- medication to treat heart palpitations
- medication, such as insulin, to treat diabetes
- surgery to correct abnormal spine curvatures.
Research into the function of the deficient protein, frataxin, may offer potential for future beneficial treatments.
Where to get help
Things to remember
- Friedreich ataxia is a relatively rare inherited disease of the nervous system characterised by gradual loss of coordination.
- To the casual observer, a person with Friedreich ataxia may seem to be drunk.
- The symptoms of Friedreich ataxia are caused by the gradual deterioration of nerve cells (neurones) in the spinal cord and brain.
- There is no cure, but some of the symptoms can be managed with medication and physical therapy.
This page has been produced in consultation with and approved by:
Muscular Dystrophy Association
Page content currently being reviewed.
Content on this website is provided for education and information purposes only. Information about a therapy, service, product or treatment does not imply endorsement and is not intended to replace advice from your doctor or other registered health professional. Content has been prepared for Victorian residents and wider Australian audiences, and was accurate at the time of publication. Readers should note that, over time, currency and completeness of the information may change. All users are urged to always seek advice from a registered health care professional for diagnosis and answers to their medical questions.