DNA-Based Blood Test More Accurate in ID of Down Sx

Share this content:
DNA-Based Blood Test More Accurate in ID of Down Sx
DNA-Based Blood Test More Accurate in ID of Down Sx

THURSDAY, April 2, 2015 (HealthDay News) -- A DNA-based blood test appears to be more effective in detecting possible Down syndrome in unborn children than other screening methods, researchers say. The test exhibited perfect accuracy in a clinical trial, detecting Down syndrome in all 38 women whose children had inherited the disorder. The findings have been published in the April 2 issue of the New England Journal of Medicine.

By comparison, standard screening methods only detected Down syndrome in 30 of the 38 expecting mothers, the study authors said. In the test, clinicians analyze fetal DNA circulating freely in a pregnant woman's bloodstream. Greater quantities of fetal DNA -- also called cell-free DNA -- in a woman's blood are an indication that her unborn child has Down syndrome. The new clinical trial compared the cell-free DNA screening test to standard first-trimester screening (with measurement of nuchal translucency and biochemical analytes).

Earlier studies of cell-free DNA screening focused on older women believed to be at higher risk for birth defects, but this trial followed 15,841 women with an average age of 31. One-quarter were over 35, the age at which women traditionally have been considered high risk.

Besides its strong accuracy, the cell-free DNA test also had a much lower false-positive rate than standard screening -- 0.06 percent, versus 5.4 percent with standard screening, the study authors said. However, despite its accuracy, mothers should follow up any positive result with an invasive diagnostic test such as amniocentesis before making any decisions regarding their pregnancy, Joe Leigh Simpson, M.D., senior vice president of research and global programs at the March of Dimes in White Plains, N.Y., told HealthDay. "This [new test] is a major advance, but you're still going to have to confirm the results," he said.

The clinical trial was funded in part by Ariosa Diagnostics, manufacturer of a cell-free DNA prenatal screen.

Full Text
Editorial
Letter to the Editor
Brief Report

Share this content:

is free, fast, and customized just for you!




Already a member?

Sign In Now »

Drug Lookup

Browse drugs by: BrandGenericDisease



Sign up for myCME e-newsletters




More in Home

U.S. High School Students Report Sport-Linked Concussion

U.S. High School Students Report Sport-Linked Concussion

Overall, 15.1 percent of students reported having at least one concussion in the previous 12 months

Corneal Abnormalities Seen With Down Syndrome

Corneal Abnormalities Seen With Down Syndrome

More than 70 percent of patients in Down syndrome group had traits compatible with keratoconus

Many Childhood CA Survivors Not Concerned About Future Health

Many Childhood CA Survivors Not Concerned About Future ...

Even among those exposed to high radiation doses, one-third not concerned about developing cancer

is free, fast, and customized just for you!




Already a member?

Sign In Now »