Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Study reports improved method to identify fetal DNA in maternal blood samples

03.03.2004


A new method to increase the recovery of DNA from unborn babies in a blood sample from their mothers may be helpful for future development of non-invasive prenatal genetic tests to identify fetal abnormalities, according to an article in the March 3 issue of The Journal of the American Medical Association (JAMA).



"Prenatal diagnosis is useful in managing a pregnancy with an identified fetal abnormality and may allow for planning and coordinating care during delivery and the neonatal period," the authors provide as background information. "... invasive diagnostic tests (e.g., amniocentesis, chorionic villus sampling, percutaneous umbilical blood sampling) for fetal chromosomal abnormalities are highly reliable, but the procedure used for each test carries a risk for loss of pregnancy. Many patients who are candidates for these tests decline them because of the risk of pregnancy loss." The authors continue, "... the use of free fetal DNA for detecting chromosomal abnormalities has been limited by the seemingly low percentage of free fetal DNA in the maternal circulation."

Ravinder Dhallan, M.D., Ph.D., from Ravgen, Inc., Columbia, Md., and colleagues, analyzed blood samples from pregnant women to determine if the percentage of free fetal DNA could be increased by using formaldehyde to stabilize blood cell membranes and reduce the number of the mother’s blood cells that are destroyed during sample collection, handling, and processing, which reduces the amount of maternal DNA released, thereby increasing the percentage of fetal DNA. The study was conducted in two phases from January through February 2002 at one clinical site and March 2002 through May 2003 at a network of 27 clinical sites in 16 U.S. states. The first phase collected two samples of blood from ten pregnant women - one blood sample was treated with formaldehyde and the other blood sample was untreated. In the second phase, all 69 blood samples were treated with formaldehyde.


"In the first phase of the study, the mean (average) percentage of free fetal DNA in the untreated samples was 7.7 percent, while the mean percentage of free fetal DNA in the formaldehyde-treated samples was 20.2. percent. In the second phase, a median (half-way point) of 25 percent free fetal DNA was obtained for the 69 formaldehyde-treated maternal blood samples. Approximately 59 percent of the samples in this study had 25 percent or greater fetal DNA, and only 16 percent of the samples had less than 10 percent fetal DNA. In addition, 27.5 percent of the samples in this study had 50 percent or greater fetal DNA."

The authors conclude, "When samples have a high percentage of free fetal DNA, the difference between the expected ratio of the chromosomes for a healthy fetus and that for an abnormal fetus is greater, which makes it easier to diagnose chromosomal abnormalities," and suggest that their methods "for increasing the percentage of free fetal DNA provide a solid foundation for the development of a noninvasive prenatal diagnostic test."

Susan Higgins | EurekAlert!
Further information:
http://www.jama.com/

More articles from Life Sciences:

nachricht Researchers identify potentially druggable mutant p53 proteins that promote cancer growth
09.12.2016 | Cold Spring Harbor Laboratory

nachricht Plant-based substance boosts eyelash growth
09.12.2016 | Fraunhofer-Institut für Angewandte Polymerforschung IAP

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Electron highway inside crystal

Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.

Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Researchers identify potentially druggable mutant p53 proteins that promote cancer growth

09.12.2016 | Life Sciences

Scientists produce a new roadmap for guiding development & conservation in the Amazon

09.12.2016 | Ecology, The Environment and Conservation

Satellites, airport visibility readings shed light on troops' exposure to air pollution

09.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>