Genetic Blood Test for Down Syndrome? Not Yet
Corrected on 10/07/08: An earlier version of this article incorrectly suggested that all pregnant women should get, rather than be offered, Down syndrome screening.
Pregnant women have been waiting a long time for a blood test to definitively diagnose Down syndrome, and one may finally be on the near horizon. Researchers report in the Proceedings of the National Academy of Sciences that they've overcome a significant hurdle in providing such a test, which won't require them to sort maternal genetic material from a fetus's. Another test manufactured by Sequenom could be ready as early as June, according to the New York Times.
Neither method, though, has been rigorously tested in enough women to ensure that it will predict, with absolute certainty, which babies carry the Down genetic defect and which ones don't. The disorder occurs in as many as 1 in 800 babies and causes mental retardation, facial abnormalities, heart defects, and other problems.
At this point, the two definitive ways to diagnose Down involve inserting a needle into a woman's abdomen to draw out fetal cells—both of which carry a small risk of miscarriage, about one half of 1 percent. But, as I previously reported, a combination test is already available that's about 95 percent reliable for identifying Down, without posing any risk of miscarriage.
The American College of Obstetricians and Gynecologists now recommends that all women in their first 12 weeks of pregnancy be offered both a blood test that checks for four Down markers. While negative test results are great for reassuring mothers, any result indicating that a baby has Down still needs to be confirmed using a needle-in-the-abdomen method, either amniocentesis or chorionic villus sampling. Clearly, a new genetic blood test would be great for pregnant women, but we may still be waiting a bit before one becomes available.
Tags: pregnancy | medical screening | genetics | disability | Down syndrome
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Down syndrome
As a parent of a child who just happens to have Down syndrome I have to say that I was rather offended by the use of several statements in : "Genetic Blood Test For Down Syndrome Not Yet".
"which babies carry the Down genetic defect " We as parents of children with trisomy 21 do not consider our children as having a "DEFECT" and it is certainly not a "Down" defect. Our children are children who happen to have Down syndrome...not a Downs child.
"But, as I previously reported, a combination test is already available that's about 95 percent reliable for identifying Down, without posing any risk of miscarriage." IDENTIFYING DOWN SYNDROME WOULD HAVE BEEN A MORE APPROPRIATE WORDING. People first language is something that you, as a writer, should look into.
baby's neck (another sign of Down). AGAIN....ANOTHER SIGN OF DOWN SYNDROME WOULD HAVE BEEN MORE APPROPRIATE. OUR CHILDREN ARE CHILDREN FIRST AND NOT A SYNDROME
result indicating that a baby has Down still needs to be confirmed using a needle-in-the-abdomen. HAS DOWN...AGAIN HAS DOWN SYNDROME!!!
With October being Down Syndrome Awareness month...people first wording would be appreciated. Please visit the National Down Syndrome Society for information on presenting appropriate language in text.
genocide
As a fetal medicine specialist, it is is fascinating to have witnessed the changing attitudes and methods used in screening for Down syndrome (DS) over the years.
What we all forget is that the majority of governments would like to see all pregnancies screened and the pregnancies terminated with DS terminated.
This can be seen as a move forward, to remove the imperfect, the save society money, to save families the hardship of challenging times etc etc
As so eloquently described above by the parent of a child with DS - DS is the same as being white black yellow or pink colour. we as a society have to seriously perform a reality check and look inwards to ourselves as the strength of a society is measured by the manner in which we care for our weakest. For this reason are we as a society just far to selfish to contemplate 'imperfection' as viewed by some?
Your article is informative and I can see that this is simply reporting something scientific but at the same time the ethical issues are even more important perhaps for us all to consider ever again.
Some positive thoughts...
Please consider the fact that current procedures (invasive) give a false positive reading of about 15% of all women tested. That means this newer, non-invasive test will actually help to reduce the number of abortions, therefore actually saving lives. Indeed, there might come a time, let's hope soon, when doctors will be able to rectify a genetic disorder before birth takes place Let's stay positive about positive developments in life, wherever we might find them. This includes the love and happiness & joy of parents who have children with Downs.
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