Almost a year after the adoption of the reform of bioethics laws, a new measure is about to materialize. As of this fall, the first genetic neonatal screening study will be carried out in France, to detect spinal muscular atrophy at birth. This childhood neuromuscular disease is one of the most common (around 100 cases per year) and progressively destroys the motor neurons that control movement. In its most serious form, half of the children die before their second birthday, victims of difficulty eating or breathing.
Since 2017, treatments have appeared – developed by the Biogen, Novartis and Roche laboratories – but do not make it possible to combat the irreversible degradation of neurons. “Almost half of babies with the most severe form of spinal muscular atrophy do not benefit from these treatments and die because they are detected too late by the health system. It’s unacceptable as a parent.” whispers Christian Cottet, general manager of AFM-Téléthon.
This is the whole point of neonatal genetic screening: “We must be able to use these treatments in the best therapeutic window, and therefore detect the disease before the appearance of the first symptoms”, argues Vincent Laugel, neuropediatrician at the Strasbourg University Hospital.
saving babies
This experiment was made possible by an amendment to the bioethics law, adopted in August 2021. It had, at the time, been the subject of much controversy, some politicians like the deputy LR Patrick Hetzel (Bas-Rhin) going so far as to speak of risks of“eugenics”. But, on this specific case, the project leaders assure and are pleased that a scientific and political consensus has been established.
“We conduct the test on babies who are bornreassures Vincent Laugel. We are only going to detect this disease, there is no question of going to look for things in secret or of testing any other genetic disease. »
Concretely, the pilot study, named Depisma, will deploy this screening in two regions, the Grand Est and New Aquitaine, for two years. The objective: to demonstrate the large-scale feasibility of genetic screening at birth. «We will test hundreds of thousands of babies and, according to our estimates, detect 32 with spinal muscular atrophy,” explains Vincent Laugel. They will therefore be able to receive one of the existing treatments and should be able to live normally. ” It’s urgent, says Didier Lacombe, geneticist at the Bordeaux University Hospital. Thanks to this device, we will be able to save babies! »
Routine screening elsewhere
This detection could then be extended to the whole country. A first, while this screening is already systematic in Belgium, Germany or in a large part of the United States. In France, the current screenings for newborns consist of taking a drop of blood from the finger or the heel, to see if it contains any unusual elements. Six diseases, such as cystic fibrosis, are concerned.
But spinal muscular atrophy can only be detected genetically, by directly identifying a mutation in the gene concerned. However, French legislation has long been very restrictive in this area, framing genetic screening by a series of in-depth interviews with parents. “An unthinkable procedure for general screening of 740,000 births each year”, explains Christian Cottet. Now, as part of the experiment, a second drop of blood will be taken to perform a genetic test.