According to a new study reported in the British Medical Journal, a new DNA blood test may potentially reduce the need for invasive procedures such as amniocentesis as much as by 98 percent.
Amniocentesis is the process by which a small amount of amniotic fluid is removed from the amniotic sac, using a needle to test for fetal abnormalities. This method helps determine the baby’s sex, assess his lung’s maturity or assess his overall wellbeing.
Another test, called chorionic villus sampling, also involves sticking a needle into the uterus or placenta to extract fetal DNA.
Said head of the genetics and genome biology program at the Hospital for Sick Children in Toronto, Stephen Meyn, “There is discomfort to the mother and the risk of loss of pregnancy so these tests are not ideal.”
This new test is reportedly accurate when it comes to seeing whether a fetus carries an extra pair of chromosome 21, and it does not come up with false negative results, says Dennis Lo Yuk-Ming, chemical pathology professor at The Chinese University of Hong Kong.
The downside, however, is that the test is costly and there is still a chance to get false positives.
753 women at risk for Trisomy 21, or the medical term for Down’s Syndrome, were tested for the study. 86 of these women carried a fetus with the chromosomal disorder.
Meyn cautions, still, that a lot of factors surrounding the new DNA blood test will have to be resolved first before it can become part of clinical practice.
Down’s Syndrome is a condition wherein one has three copies of chromosome 21, rather than the normal two. People with Down’s Syndrome have some recognizable characteristics such as a flat face, short neck and strangely-shaped ears. Those afflicted with this condition suffer from certain learning disabilities such as congenital heart disease, intestinal problems, cataracts as well as early dementia.
Around 35,000 people in the world have Down’s Syndrome.
SOURCES: • January 12, 2011. “New test for Down syndrome could reduce invasive procedures,” world-countries.net < http://world-countries.net/archives/109455 > • “Blood test can rule out Down’s syndrome without invasive tests,” Besthealth.bmj.com < http://besthealth.bmj.com/x/news/552448/news-item.html > • Atula. January 13, 2011. “New Test for Down’s Syndrome Promises More Accurate Results” GrowingYourBaby.com < http://www.growingyourbaby.com/2011/01/13/new-test-for-downs-syndrome-promises-more-accurate-results/ >