Critically used trisomy tests have been widely used
Controversial trisomy tests used 10,000 times
03/17/2014
Pregnant women can use a blood test to determine if their unborn child has Down syndrome. These trisomy tests have been used approximately 10,000 times since their launch in 2012. But critics are still calling for a ban on these tests.
Test has been heavily criticized since its introduction
On 21st March, World Down Syndrome Day, events are organized around the world to increase public awareness of the issue. On this occasion, discussions about a controversial diagnostic method will certainly arise again. Because the Trisomie blood test of the Konstanzer company Lifecodexx, is strongly since its introduction in the year 2012 with terms like „selection“, „Discrimination against disabled people“ and „illegal“ been criticized. As various newspapers with reference to the news agency dpa report, says the Medical Director of Lifecodexx, Wera Hofmann, but that the test has now established. However, the disabled representative of Baden-Württemberg, Gerd Weimer, holds against: „The designer baby stands out on the horizon.“ He continued: „This must be understood and discussed socio-politically.“
From the completed ninth week of pregnancy
With the help of a blood sample of pregnant women, the so-called „PraenaTest“ exclude or confirm trisomies 21, 18 and 13 in the unborn child. Since its launch in August 2012, the test has been used on several thousand pregnancies. „We're getting close to the 10,000“, says Marketing Manager Elke Decker. Of these, about half of the blood samples came from Germany, but the test was also applied worldwide. Samples were also sent from Switzerland, Hungary, Bulgaria, Turkey and Dubai. The test will be conducted in women who have completed the ninth week of pregnancy and who are at increased risk for the trisomies of the unborn child. The costs of 825 euros would have to be paid by the patients themselves. When a woman decides to take the test, the doctor's office sends blood samples to the company containing fragments of the genome of the mother and child.
Date for World Down syndrome day chosen deliberately
The laboratory then uses the blood sample in several steps to extract the genome from which the child's DNA is determined, provided that its share in it is at least four percent. „We then look to see if the amount of childhood genetic material for a given chromosome is elevated to determine a corresponding trisomy in the unborn child“, Hofmann says. For example, in Down's syndrome, the 21st chromosome is present in triplicate. Characteristic of this are physical abnormalities and a diminished intelligence. For the World Down Syndrome Day, which refers to this trisomy 21, the date was deliberately chosen: March 21 symbolizes the threefold presence of the 21st chromosome. In Germany are next to the „PraenaTest“ There are currently two more non-invasive tests available. For one thing „Panorama Test“ the companies Natera and Amedes, which has been on the market since summer 2013, as well as the „Harmony test“ the US company Ariosa, which is available since autumn 2013. In both tests, the evaluation takes place in the USA.
Great accuracy of such blood tests confirmed
As Heinz-Alfred Hagemann from the professional association of established prenatal physicians (BVNP) said, Lifecodexx was a pioneer in Germany's approved, non-invasive tests. The company is also oriented „very stringent in the gene diagnostics law“ and have initiated a follow-up study in Germany. According to the company, the study will check in practice after delivery if the result was correct. The accuracy is therefore at 99 percent. The great accuracy of such blood tests has been recently demonstrated in a „New England Journal of Medicine“ published study confirmed. Thus, they rarely provide incorrect results than the conventional examination methods.
Disability Commissioner calls for a ban on testing
On such tests, but there is still much criticism. Some still see discrimination against people with disabilities. The test violates „against the normal right to life set out in the United Nations Convention on the Rights of Persons with Disabilities and must be prohibited nationwide“, said the Baden-Württemberg Disability Commissioner. „We need a broad social discussion on prenatal diagnostics as soon as possible.“ In the US, there are companies that could test up to 80 parameters in the blood. „This starts with genetic defects to chronic diseases such as rheumatism or asthma“, So Weimer. He worried that once this was applied in Germany, the pressure would be too great for the people who bring a sick child to the world without a previous test. „I think that's a terrible development.“ Shortly after the test was launched, Caritas Disability Assistance had called on politics and society, „to strongly advocate for a society of diversity that also welcomes children with genetic disabilities in their midst.“ In your „Bonn Declaration“ demanded the organization, „Any form of public social pressure on parents of disabled children must be countered.“
Tests contain only limited amount of information
Lifecodexx rejects criticism of the tests. Hofmann says: „We perceive this as an excuse.“ The non-invasive blood tests, in contrast to the conventional invasive tests, for example by puncture of the suckler cake, are risk-free. „Our company has decided to allow these tests. Now criticizing the faster access is threadbare.“ Of the analyzes carried out so far, 98 percent are inconspicuous. „If these women were all examined invasively, they would be at unnecessary risk of miscarriage.“ However, an inconspicuous test result does not automatically mean that the child is healthy. „About four percent of all newborns have hereditary disease“, Hofmann says. „Other illnesses arise, for example, from complications before, during and immediately after birth.“ Hagemann also said that the tests included only a limited amount of information. „They can only say something about the genetic dispositions“, so the doctor. „But nothing about an evaluation of the whole child and his quality of life.“ (Ad)
Picture: Gerd Altmann, Pixelio