News / Health

Scientists Work on Fetal Test Using Mothers' Blood

Scientists Work on Fetal Test Using Mothers' Blood
Scientists Work on Fetal Test Using Mothers' Blood
Jessica Berman

A simple maternal blood test might someday be able to tell pregnant women whether the children they are carrying have diseases.   The test would screen for more disorders than current prenatal tests, and researchers say it would be much safer.  

Scientists say they have found a way to isolate a growing fetus' hereditary DNA from the plasma, or liquid portion, of the mother's blood and construct a genomic map of the fetus.  

Researchers report being able to decode 94 percent of a developing fetus' genome from a sample of maternal blood, searching for disorders that are currently not detected with the two available prenatal screening tests.  Those tests -- amniocentesis and chorionic villus sampling -- are considered invasive and carry some risks to the mother and the developing fetus.

With amniocentesis, a doctor uses a long needle to extract a sample of fluid from the womb at around 20 weeks gestation to test for chromosomal abnormalities, infections and metabolic defects.  But there is a risk of fetal injury and miscarriage, as there is with chorionic villus sampling.

Dennis Lo of the Chinese University of Hong Kong says women who undergo that procedure, in which a sample of placental tissue is taken to examine for chromosomal mutations, run a one percent chance of miscarriage -- even if the baby is normal.

"So pregnant women, when they undergo those tests, will usually have a lot of psychological stress," Lo said. "So basically, our technology will bring [i.e., make] prenatal testing safer for the babies and less stressful for the mothers."

There are 46 chromosomes in the nucleus of a human cell, with each parent contributing 13 chromsomes.  Chromosomes are long segments of DNA instructions.

Amniocentesis and chorionic villus sampling look for chromosomal abnormalities.  It is a crude screening tool compared to what might be possible with analyzing the letter sequences of fetal DNA.

In what researchers call a "proof-of-concept experiment," Lo and a team of scientists assembled a fetal genome from fragments of DNA from the blood of a pregnant woman who, along with her husband, carried genes for a life-threatening form of anemia, a shortage of oxygen-rich red blood cells.

According to Lo, researchers were able to detect genetic abnormalities in the fetus.

"So this is a breakthrough in this paper.  In the first half, we show that the entire fetal genome is there," Lo said. "In the second half, we actually sample the fetal genome and scan it for [a] disease the baby may have."

Lo says a prenatal test that scours the billions of letters comprising the fetal genome are prohibitively expensive -- around $200,000 dollars.  But he says the goal is to develop prenatal screening that targets particular genetic abnormalities within certain populations.

"For example if you look at Southeast Asia, then there's a whole bunch of genetic anemias which are common here," Lo said. "In the Caucasian population, you can screen for the hundreds of mutations which are causing cystic fibrosis.  In an African population, you can use this to detect sickle cell anemia.  So the applications for this are numerous."

Lo predicts that scientists eventually will develop a fetal DNA test that can be used as early as nine weeks into pregnancy.  An article describing the fetal DNA test is published this week in the journal Science Translational Medicine.

You May Like

At Khmer Rouge Court, Long-Awaited Verdict Approaches

First phase of trial, which is coming to an end, has focused on forced exodus of Phnom Penh in 1975 - and now many are hopeful justice will be served More

Video When Fighting Eases, Gazans Line Up at Bakeries

When there is a lull in the conflict, residents who have been hunkered down in their apartments rush out to stock up on food and other necessities More

Video Information War Rages Alongside Real One in Ukraine

Downing of Malaysian airliner, allegations of cross-border shelling move information war in war-torn country to a new level More

This forum has been closed.
Comments
     
There are no comments in this forum. Be first and add one

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
Information War Rages Alongside Real One in Ukrainei
X
Al Pessin
July 31, 2014 8:13 PM
The downing of the Malaysian airliner two weeks ago, and allegations that Russians are shelling Ukrainian troops across the border, have moved the information war swirling around the Ukrainian conflict to a new level. VOA's Al Pessin reports from Kyiv.
Video

Video Information War Rages Alongside Real One in Ukraine

The downing of the Malaysian airliner two weeks ago, and allegations that Russians are shelling Ukrainian troops across the border, have moved the information war swirling around the Ukrainian conflict to a new level. VOA's Al Pessin reports from Kyiv.
Video

Video When Fighting Eases, Gazans Line Up at Bakeries

When there is a lull in the conflict in Gaza, residents who have been hunkered down in their apartments rush out to stock up on food and other necessities. Probably the most important destination is the local bakery. VOA’s Scott Bobb reports from Gaza City.
Video

Video US-Funded Program Offers Honduran Children Alternative to Illegal Immigration

President Obama and Central American leaders recently agreed to come up with a plan to address poverty and crime in the region that is fueling the surge of young migrants trying to illegally enter the United States. VOA’s Brian Padden looks at one such program in Honduras - funded in part by the United States - which gives street kids not only food and safety but a chance for a better life without, crossing the border.
Video

Video 'Fab Lab' Igniting Revolution in Kenya

The University of Nairobi’s Science and Technology Park is banking on 3-D prototyping to spark a manufacturing revolution in the country. Lenny Ruvaga has more for from Nairobi's so-called “FabLab” for VOA.
Video

Video Gazans in Shelled School Sought Shelter

Israel's air and ground assault against Hamas-led fighters in Gaza has forced many Palestinians to flee their homes, seeking safety. But safe places are hard to find, as VOA’s Scott Bobb reports from Jabaliya.
Video

Video Rapid Spread of Ebola in West Africa Prompts Global Alert

Across West Africa, health officials are struggling to keep up with what the World Health Organization describes as the worst ebola outbreak on record. The virus has killed hundreds of people this year. U.S. President Barack Obama and other world leaders are watching the developments closely as they weigh what actions, if any, are needed to help contain the disease.
Video

Video Michelle Obama: Young Africans Need to Embrace Women's Rights

U.S. first lady Michelle Obama urged some of Africa's best and brightest to advocate for women's rights in their home countries. As VOA's Pam Dockins explains, Obama spoke to some 500 participants of the Young African Leaders Initiative, a six-week U.S.-based training and development program.
Video

Video Immigrant Influx on Texas Border Heats Up Political Debate

Immigrants from Central America continue to cross the U.S.-Mexico border in south Texas, seeking asylum in the United States, as officials grapple with ways to deal with the problem and provide shelter for thousands of minors among the illegal border crossers. As VOA's Greg Flakus reports from Houston, the issue is complicated by internal U.S. politics and U.S. relations with the troubled nations that immigrants are fleeing.
Video

Video Study: Latino Students Most Segregated in California

Even though legal school segregation ended in the United States 60 years ago, one study finds segregation still occurs in the U.S. based on income and race. The University of California Los Angeles Civil Rights Project finds that students in California are more segregated by race than ever before, especially Latinos. Elizabeth Lee reports for VOA from Los Angeles.

AppleAndroid