A FRENCH TEAM OBTAINS PROMISING RESULTS IN THE TREATMENT OF AN ILLNESS OF GENETIC ORIGIN.


By Jean-Yves Nau.

A group of biologists and of French doctors have just announced that they have achieved, for the first time, promising results in the treatment of Friedreich's Ataxia, a hereditary illness of serious consequences due to the degeneration of neurons of the spinal marrow.
This announcement, published in the columns of the weekly British doctor's The Lancet last number (August 7), was carried out by the team of geneticists of the unit 393 of the National Institute of the Health and of the Medical Investigation (Inserm) – Pierre Rustin, Jürgen-Christoph von Kleist-Retzow, Karine Chanterel-Groussart, Arnold Munnich and Agnès Rötig, and Doctor Daniel Sidi (service of pediatric cardiology, hospital sick Necker-boys, Paris).
In view of the first results obtained starting from a simple treatment medicamentoso, a rehearsal has just been presented in great scale in collaboration with the hospital group Pitié-Salpêtrière for a two year-old duration with fifty two sick persons, of which twenty were children.
The illness -or ataxia - of Friedreich it was described for the first time in 1863 by the German neurologist of which takes the name. It is translated in the appearance, between five and fifteen years, of quick progressive alterations of the motive coordination and sensitivity. The intellect of the sick persons is habitually preserved. He/she didn't prepare until the present of any treatment and the survival rarely passes the principle of the mature age.
The death is often due to the heart anomalies (cardiomiopatía) that are associated to the degenerative lesions of the neurons. The ataxia of Friedreich is the most frequent in the illnesses classified in the group of hereditary ataxias. »
It is considered that in Europe a person on hundred twenty is portadora of the genetic anomalie that originates the symptoms and of the observed pathology. This anomaly is not bound to the sex and it is transmitted in a recessive way. The payees of the anomaly are not affected if of this last one it doesn't exist more than in a single copy in the breast of their hereditary patrimony. On the other hand, two parents «  payees «  can have sick children.

An encouraging rehearsal: less than ten years Ago, a London team was able to locate in the chromosome number 9 the gene, a priori, implied in this illness. At once, thanks to the works of Doctor Michel Koening's team (Strasbourg) and to the new tools of genetic discovery given by the Center of study of the human polimorfismo (Paris), as well as to the collaboration of about two hundred families concentrated on France, Italy and Spain, you can fence the critical area more finely (it Hulls at March 9 1996).

The results obtained today for the investigating Parisinos they mark a new stage in the understanding and the correction of the processes fisiopatológicos of this illness. These results are so much more important when they don't belong together with the habitually proposed outlines and worked in the field of the human pathology.

This way, far from inserting a fragment of genetic information they aspire to correct the anomaly, and far from administering the absent or abnormal protein characteristic of this anomaly, the authors of the publication of Lancet have tried to correct, simply, one of the pathological mechanisms that had been found: an abnormal accumulation of iron in certain structures intracelulares –the mitocondrias -, I agree of the cellular breathing and of the energy production. This excess of iron load leads to the appearance of toxic molecules for the cells (free radicals).

After the test in vitro, a molecule -idebenone - it has been shown more effective and more private of secondary effects. A first rehearsal has been presented in three sick youths during one period from four to nine months. « The results are stimulating. In little time, the heart hipertrofia that can be mortal in this illness, it has diminished significantly and the product has been tolerated the authors of the study perfectly they -specify -. « The short duration of this rehearsal has not allowed to notice a change at the levels of the neurological anomalies, but the circle of the ailments has noticed an improvement of the muscular force and of the precision of the movements. »

The results of the rehearsal presented in near fifty two patients they will allow to say if the progresses observed in the knowledge of the molecular genetics can be prolonged by a classic pharmacological access. If this was the case, the therapeutic perspectives would be enlarged considerably.