January 14, 2011

Blood Test for Down’s Syndrome

(Ivanhoe Newswire) -- A test that uses the latest DNA technology to analyze genetic components in a pregnant woman's blood could predict Down's syndrome in unborn babies, according to new research.

Down's syndrome occurs when an individual has three, rather than two, copies of the 21st chromosome. This additional genetic material alters the course of development. Older women are at a higher risk of giving birth to a baby with Down's.

Women in high-risk groups typically undergo a combination of scans and hormone tests to determine if they need to have an invasive test like amniocentesis or chorionic villus sampling -- where doctors take samples of genetic material from the fetus.

A research team, led by professors from The Chinese University of Hong Kong, tested blood samples from 753 pregnant women who were at high risk for having a baby with Down's. They found 86 of the women were carrying a baby with Down's syndrome.

The authors say the results showed the blood test is highly accurate in detecting Down's syndrome and did not give them false negative results. The say this test could mean that 98 percent of invasive procedures to detect Down's could be avoided.

SOURCE: British Medical Journal, Jan. 2011