New disease diagnosed at birth
New disease diagnosed at birth
By 2020, the MCAD deficiency, a sometimes lethal genetic disease, will be detected at birth. This measure brings to six the number of pathologies detected in newborns. A low figure compared to other European countries.
A new medical test at birth. Neonatal screening, which now focuses on five serious diseases, will be supplemented by the detection of an additional disease in the first quarter of 2020, according to Health Minister Agnès Buzyn. The announcement was made on November 5th, on the occasion of the 6th edition of the RARE 2019 Meetings organized in Paris by the Rare Diseases Foundation. Nearly three million euros must be used to finance the equipment needed for this new screening.
MCAD deficiency, sometimes fatal
But what pathology is it? This rare disease is called MCAD deficiency. It is an inherited disease that occurs between three and 24 months after birth. It is characterized by an inability of the body to use certain fats, fatty acids, as a source of energy. It can cause lethargy, vomiting, and be fatal in the absence of intervention.
Its screening was recommended in 2011 by the High Authority for Health (HAS) "because it prevents preventable deaths easily preventable in young children," said this body. "The management, very effective, is to observe simple dietary rules," noted then the HAS.
France lags behind in neonatal screening
France currently only identifies five serious diseases at birth: cystic fibrosis, congenital hypothyroidism, phenylketonuria, congenital adrenal hyperplasia and sickle cell disease. Screening for this last disease is practiced only in newborns in overseas and, in mainland France, in those whose parents are from "at risk" regions (including Africa, Middle East, Indian Ocean and West Indies). Since 2012, deafness is also detected at birth.
This screening table appears very meager in comparison with those practiced for example in Belgium where a dozen diseases are detected or in Sweden or Austria, where the neonatal screening targets no less than 24 serious diseases. A French delay in this area already pointed out a few months ago by Nathalie Triclin, president of the Alliance of rare diseases.
The HAS, seized to extend the indications of this screening at birth, "will render by the end of the year an opinion on screening for severe combined immunodeficiency (SCID) and other inborn errors of metabolism (EIM) "that the deficit MCAD, as well as on" the extension of screening for sickle cell disease in the metropolis ", continued Ms. Buzyn.
Still no neonatal genetic exams
What about genetic exams? This decision will come back to HAS, according to the minister. Last October, during the examination of the draft Bioethics law in the National Assembly, the deputies in favor of including genetic tests in the neonatal screening were not followed. To the chagrin of associations of patients and parents of patients who denounced this status quo.
"The impossibility of performing targeted genetic tests at birth is clearly a loss of luck for babies born today," responded in October the AFM-Telethon. Indeed, some genetic diseases such as spinal muscular atrophy, which affects one in 6 to 10,000 births in France, are seeing new effective treatments. And these treatments are "more effective" if they are "administered early before the appearance of the first symptoms," also said the AFM-Telethon.
The finding is the same for preimplantation diagnosis (PGD), referred to the National Assembly. This test is currently reserved for couples who already have a seriously ill child. If extended, it would allow, in the case of in vitro fertilization, to select non-carrier embryos of a given mutation. "Why healthy couples can choose to detect trisomy 21 during pregnancy but not 'more serious' diseases such as cystic fibrosis or spinal muscular atrophy" before implantation of an embryo, deplored Professor Pascal Pujol, geneticist, interviewed last September by Allodocteurs.fr.
Concretely, this would be to announce a risk to the parents before the implantation of the embryo and thus would not imply a medical termination of pregnancy. "In the case of Spinal Muscular Atrophy, which most often has no family history, PGD would avoid giving birth to a child who has a 50% risk of dying before the age of 24
months" argued the Professor Pujol.
A practice still prohibited in France - although the genetic society and the ethics council are favorable - but already authorized in Belgium, the Netherlands, Israel or the United States.