Nicholaus Friedreich was Professor of Medicine in Heidelberg, Germany, when he first described the disease which bears his name. He wrote a series of articles about nine patients with Friedreich’s Ataxia between 1863 and 1877. By the end of the nineteenth century a considerable number of similar patients had been diagnosed as having the same condition and the disorder was first discussed at the Medical Society of London in 1880.
What is Friedreich’s Ataxia?
Friedreich’s Ataxia (FA), is an uncommon, slowly progressive disease of the nervous system, causing an inability to co-ordinate voluntary movements. Control of the muscles is severely impaired, and unsteadiness of walking, clumsiness and tremor of the hands, a tendency to trip and slurring of the speech soon become prominent. Intelligence and the special senses are unimpaired. In the majority FA may affect other parts of the body apart from the nervous system. About two-thirds of people have an abnormal electrocardiogram (ECG) indicating an abnormality of the heart muscle. Nevertheless, this rarely causes symptoms apart from occasional palpitations in a small proportion of people with the disease. The heart muscle usually manages to work normally, although heart failure occurs earlier on average than it does in the rest of the population. Diabetes is more common amongst people with FA; it occurs in about 10 per cent of cases.
At what age do signs of Friedreich’s Ataxia appear?
The age at which people develop FA varies considerably. Symptoms usually start between the ages of 4 and 16. By their early twenties most affected people may need a wheelchair, and by their mid forties nearly all are unable to walk.
Does the rate of progression vary?
The symptoms of FA are slowly progressive. The unsteadiness usually results in the inability to walk within 8 to 10 years following onset of symptoms. During the course of the disease, leg muscles continue to weaken, and a wheelchair is the only sensible means of getting around when this stage of the disease is reached. People can then maintain general independence for a considerable time. The time however varies greatly and some people remain mobile for much longer. As arms and hands become increasingly unco-ordinated, the person may experience difficulty in self-feeding, and as the disease advances, handwriting and articulation may become progressively more difficult. In general terms, people who are physically disabled tend to have a life expectancy somewhat shorter than average, and this also applies to those with FA.
How is a diagnosis of Friedreich’s Ataxia established?
The onset of the disease is insidious and may not be recognised for months or even years; people may be thought to be ‘just clumsy’ by their parents and friends. Unsteadiness is the most frequent initial symptom and is worse in the dark or if the eyes are closed; co-ordination is also affected. Sometimes walking is abnormal from the start. The diagnosis is made on the basis of history taking and a detailed neurological examination. Various tests, including the ECG and electrical nerve conductions tests, provide useful supplementary information for the doctor. There is no specific blood or other test for FA at present. It is easier to diagnose the condition early if an older brother or sister is affected, but no test is available which predicts which children have the disease before symptoms or signs develop. A number of other diseases of the nervous system may be confused with FA and it is important for those suspected of having it to be assessed by a neurologist.
Is Friedreich’s Ataxia always inherited?
FA is inherited as a recessive gene from both parents (who are unaffected), and may occur in several children in a family. Many people with FA do not have any similarly affected relatives.
How does inheritance work?
“Autosomal Dominant Inheritance” is a name used to describe a situation where a child inherits a condition or characteristic from ONE of its parents. This will give rise to symptoms of disease when the gene that is inherited is abnormal because, being dominant its influence overrides that of the corresponding normal gene inherited from the other parent. “Autosomal Recessive Inheritance” describes a quite different situation where an abnormal gene inherited from one parent only gives rise to disease if the corresponding gene inherited from the other parent is identically abnormal.
In this case, both parents may be physically normal although they are each carrying one (the same) abnormal gene. This is the usual situation in FA.
Genes exist in the nucleus (control centre) of all the cells of the body. Most genes are in pairs and each pair governs a particular characteristic of the person, eg colour of hair. Some gene-pairs control less obvious characteristics, eg production of a certain chemical molecule within cells. Abnormalities in this kind of gene possibly cause many of the known “inheritable” disorders, eg FA.
For more information about the genetic implications for FA, please contact the Muscular Dystrophy Association
What causes Friedreich’s Ataxia?
It is known that FA is caused by an abnormality of the genetic code; the exact nature of this abnormality is unclear. A considerable amount of research is currently directed towards establishing what is the basic defect in FA.
Is there any treatment for Friedreich’s Ataxia?
Although, at this time, there is no treatment to alter the progression of the disease, physiotherapy, orthopaedic aids and appliances may be prescribed to assist affected people and their families. A number of therapies have been tried, including the administration of drugs called choline, lecithin and physostigmine. All the properly conducted trials assessing these drugs have failed to show any long term benefit. Cell implant therapy, which has been given to people in Germany, has no rational scientific basis and is potentially dangerous. The same applies to injections of calcium and other substances. No trials of these latter two treatments have been reported in the medical press, and they are not recommended by medical advisers.
Although FA cannot be cured, some treatments are available for specific problems. If curvature of the spine or high arched feet present major problems, surgery can be undertaken but the need for this should be assessed very carefully. Measures may be required to prevent spinal deformity. Drugs are available to prevent or lessen palpitations and spasms of the legs, and also to treat diabetes. It is important for all FA sufferers to be as active as possible. There are no restrictions on exercise apart from those of the disease itself. Swimming is an excellent form of exercise as it does not require particularly good strength or co-ordination and it uses most of the muscles in the body. People should be aware of the fact that difficulty in walking may be accentuated by periods of bed rest, so these should be kept to a minimum. Obesity should also be avoided as it decreases mobility. Special diets may keep weight down and so allow better use of weakened muscles but otherwise are not known to alter the course of the disease.
Can laboratory tests detect carriers of Friedreich’s Ataxia?
At present, there is no test for ‘carrier detection’, but discoveries indicate that the cause of FA and the possibility of carrier detection are both within the reach of science.
What research is being done?
Active research is in progress in many centres around the world where scientists are studying FA and looking for clues concerning the causes, with the aim of increasing our understanding of this disease. Among the areas being researched are trophic factors (substances that allow tissues to grow and survive – a little like fertilisers on plants), enzymes (enzymes are proteins which catalyse or speed up chemical reactions necessary for the body’s function), neurotransmitters and neuro-modulators (these are substances which are used to transmit messages and modify messages transmitted from one cell to another) as well as the relationship of diabetes to FA, heart involvement and the microscopic structure and chemistry of muscle and other tissues in FA people.
There has been considerable interest recently in the observations from one laboratory that there appears to be a deficiency of an enzyme called Malic Enzyme in skin cells from FA people. It is possible that this kind of study could provide insight into both the cause of the disease and methods of carrier detection in FA. It is interesting, for example, that Malic Enzyme is found at its highest concentrations in the heart and nervous system in normal people which could explain why these same tissues are involved if Malic Enzyme levels are too low in FA people. Further studies of these clues are continuing. Meanwhile it is both appropriate and encouraging that other investigators are pursuing different lines of research.
* Source : Muscular Dystrophy Association Inc
