Described in 1881 by the German neurologist Nicolas Friedreich, Friedreich's Ataxia is a progressing neurological disease.
It is the most frequent of the hereditaryAtaxias
and it affects approximately 1 person out of 30'000.
This disease with autosomic
recessive
transmission,begins generally either in childhood, adolescence
or young adulthood. Clinical symptoms associate cerebellous ataxia,
pyramidal syndrome with Babinski
sign , abolition of reflexes, disorder of profound sensitivity,
dysarthria,
oculomotor
disorders and cardiomyopathy.
Other signs are inconstant, such as the presence of hollow feet, scoliosis,
decrease of the auditive acuteness or diabetes.
This disease has a severe evolution, with loss of autonomy, requiring
the use of a wheel chair.
Until now, no treatment has shown efficacy.
The assumption of responsibility of the patients limits itself to monitoring
and functional rehabilitation.
The genetic studies, undertaken since the end of 1980, have lead to discovery in
1996 of the Friedreich's ataxia gene.
 |
Normal
chromosome |
 |
Chromosome with the Ataxia gene |
|
 |
Normal person |
 |
Person with Friedreich's Ataxia |
|
 |
Healthy
carrier that transmit the FA gene
without being ill |
|
 |
 |
|
 |
 |
|
 |
After having been identified on the long arm of chromosome 9, the
gene responsible for this disease has recently been identified by the
team of Michel Koenig.
Indeed, we know now that it codes for the frataxine,a
216 amino acids protein, contained in mitochondrion.
Following the decrease in the expression of this protein among patients,
the researchers came to the conclusion that they were in the presence
of a disease caused by loss of function of the frataxine.
Recently, a team of French researchers identified the functional
anomaly responsible for the disease among patients affected by Friedreich
Ataxia, a deficit of the mitochondrial respiratory chain, due to an
attack by free
radicals.
Indeed, there is an iron overload in the mitochondria,
that generates highly toxic oxygenated radicals for the respiratory
chain.
The mitochondria
presents several defense systems, of which the ubiquinone (Coenzyme
Q10), which is one of the components of the respiratory chain and
which has a significant antioxidant function acting upon membrane
proteins.
While using Idébénone, which has a short chain and hence is almost
identical to the ubiquinone, one obtains an efficient protection against
the free
radicals , generated by the iron overload. (It seems that quinones
ensure protection regarding the heart and the brain of patients.)
These antioxidant agents represent a new hope
of treating Friedreich's Ataxia and there is, at the present moment,
a study testing their efficiency on a group of patients.
Back home
|