Green light for early detection of trisomy 21 - The Point

The use, invasive of amniocentesis, he will soon be severely limited? Probably, according to the opinion of the Ethics Committee (CCNE). For a new diagnosis of trisomy 21 should soon be widespread. This genetic test on maternal blood, “poses no ethical problem, however it is a step forward, an advantage for pregnant women,” said Thursday Professor Jean-Claude Ameisen, Chairman of the Committee, which published a Thursday long view on the development of these genetic tests present and future.

These tests based on analysis of fetal DNA circulating in the blood of the mother, from the 11th week of amenorrhea (cessation of menstruation), can greatly reduce the use examinations as puncture of the amniotic fluid that can cause the loss of unaffected fetuses, he argued.

For now, they still can not replace the diagnosis made by chromosome analysis (“karyotype”) fetal cells taken by amniocentesis or chorionic CVS (future placenta), warns Patrick Gaudray, Research Geneticist member CCNE. Indeed, on the one hand, in 5% of cases, the results can not be interpreted for technical reasons and secondly the rate of false positives, in the order of 1/500 (or 0.2%), requires confirmation.

avoid amniocentesis 22,000 per year

“The current screening leads to a karyotype in 24,000 pregnant women at risk in 90 percent of cases is negative” and causes 80 to 240 fetal losses caused by invasive punctures says Professor Ameisen. However, he notes, the new tests are more efficient, would avoid invasive procedures such as amniocentesis to 22,000 women per year. They are often referred to as ultra-early because the decision to terminate the pregnancy can occur within the time of the abortion.

In France, the current screening for Down syndrome – which combines the study of markers in the blood of the mother to the ultrasound examination of the fetus – is proposed in the first trimester of pregnancy to all of the 800,000 pregnant women each year. The introduction of new tests should not change the rate of acceptance of screening is 85%, according to the CCNE.

1,250 euros
test

The Lejeune Foundation, opposed in principle to the screening, said that the ethics’ valid ‘modernization’ eradication of Down Syndrome “Committee.

addition to the problems of organization and control to set the extension to all pregnant women could cost up to one billion euros based on the price of 1,250 euros announced by the German company for its LifeCodexx Prenatest test, according to the Committee. However, the cost of these tests already available in countries like the United States, Germany, Austria or Switzerland, can only decrease. A Belgian company, Gendia, European representative of the Californian company Natera, already offers 850 euros.

Place disabled in question

But these tests may not become true diagnostic instruments when their false positive rate is close to zero and thus they will need more to be confirmed, has we explained to CCNE. The company must consider its emphasis Disabled, physical, psychological, and different people, noted Professor Ameisen holding that France is not up in this area, including research.

also CCNE anticipates the arrival of tests to analyze, not as part of the syndrome, but the entire genome of a fetus. They are faster and cheaper to make, says Prof. Dr. Dominique Stoppa-Lyonnet. This justifies he read the full genes unborn baby, and we will say to the mother when the parents? The Committee opened the site a vast reflection …