New screening test for Down's syndrome causes controversy
A new prenatal screening method for Down’s syndrome called PrenaTest® is causing controversy following its launch in Germany, Austria, Lichtenstein and Switzerland.
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The test, developed by the laboratory LifeCodexx, is the safest screening method yet and allows for more precise diagnosis using a simple blood sample. But Down’s syndrome associations have raised ethical concerns over the issue of purification and say that more sensitive screening moves further towards eugenics.
What is Down's syndrome?
Down’s syndrome, also known as Trisomy 21, is caused by a chromosome abnormality that occurs when the maternal and paternal chromosomes are not divided properly during the fertilisation of the egg. Once the egg is fertilised, it contains three copies of chromosome 21 instead of two. The extra chromosome causes the physical and mental characteristics of Down’s syndrome.
What does screening involve?
Antenatal screening tests for Down’s Syndrome were last reviewed in 2011 by the UK National Screening Committee*. The screening tests currently in place use nuchal translucency, maternal serum and urine markers to spot any signs of foetal anomaly in the first and second trimesters. Screening is offered to all pregnant women, whatever their age.
In devising the all-in-one integrated test, researchers hope to limit the stress and anxiety for the mother, as well as removing the need for an amniotic fluid test. This test, also known as amniocentesis, is an invasive procedure that causes miscarriages in 0.5 to 1% of pregnancies.
The first blood test for screening Down's syndrome
Scientists have focused their efforts on devising an effective non-invasive test to reduce the risks of miscarriage. The first tests were developed by the German research company LifeCodexx, which specialises in the development of molecular diagnostic techniques.
LifeCodexx developed Prenatest® in partnership with GATC Biotech. It's the first ever blood test screening method for Down’s syndrome. It means extra chromosomes can be detected in the foetus’s DNA through analysis of the mother’s blood after 12 weeks. This test is almost 100% accurate and recommended for women with a higher risk of having a baby with Down’s syndrome.
The revolutionary new technique is actually still based on the classic screening test method, but removes the need for amniocentesis. LifeCodexx says that by avoiding invasive techniques, Prenatest® reduces the risk of miscarriage caused by prenatal screening. In a press release on 20 August, the company said: “This test could save the lives of 700 unborn babies who die every year in Germany due to complications resulting from invasive procedures.”
Ethical concerns over prenatal screening
Only four countries – Germany, Austria, Lichtenstein and Switzerland – have approved the method for use in antenatal screening, but even this has sparked a wave of controversy in Europe. Down’s syndrome associations in particular have criticised the new test, while the International Federation of Down’s Syndrome Organisations has taken the matter to the European Court of Human Rights, citing the right to life of individuals with Down’s syndrome and mental and physical disabilities.
The Swiss daily newspaper Le Matin interviewed certain parties who feel that the move could lead to reduced support for families bringing up a child with Down’s syndrome in Switzerland. “Our concern is that the new screening capabilities could lead to changes in the healthcare system so that those with Down’s syndrome are no longer covered,” says Catherine Roulet, representative for the Canton of Vaud and co-president of the Vaud association for the families of individuals with mental handicaps.
*http://www.screening.nhs.uk/downs
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Posted 07.09.2012
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