Monday, Nov. 03, 2008

Blood Test for Down Syndrome

One of the best ways to confirm Down syndrome before birth is by amniocentesis, which uses a needle to remove a sample of the amniotic fluid surrounding a fetus. But needles can be nerve-wracking, especially when they're aimed at a growing baby in the womb, and the procedure carries a 1 in 200 risk of miscarriage. Now, a new genetic test may be able to pick up the disease with a simple blood sample from the mom-to-be. Because small amounts of fetal DNA enter the mother's bloodstream, the test is designed to detect abnormally elevated levels of chromosome 21 (an extra copy of it causes Down) in the mother's blood, which would indicate a baby with the disease. The test is still in the development stages, but could herald a new way to identify certain genetic conditions.