Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Detecting fetal chromosomal defects without risk

07.05.2014

Noninvasive sequencing is faster, cheaper and safer for mother and fetus, say researchers

Chromosomal abnormalities that result in birth defects and genetic disorders like Down syndrome remain a significant health burden in the United States and throughout the world, with some current prenatal screening procedures invasive and a potential risk to mother and unborn child.

In a paper published online this week in the Early Edition of PNAS, a team of scientists at the University of California, San Diego School of Medicine and in China describe a new benchtop semiconductor sequencing procedure and newly developed bioinformatics software tools that are fast, accurate, portable, less expensive and can be completed without harm to mother or fetus.

"We believe this approach could become the standard of care for screening of prenatal chromosomal abnormalities," said Kang Zhang, MD, PhD, professor of ophthalmology, founding director of the Institute for Genomic Medicine at UC San Diego and a staff physician at the San Diego VA Healthcare System.

The incidence of chromosomal abnormalities – in numbers or structure – is one in 160 live births in the United States, higher in other countries. In China, for example, the rate is one in 60 live births. The effects of these abnormalities, known as aneuploidies, can be severe, from developmental delays and neurological disorders to infertility and death. The incidence rate rises with maternal age, most notably after age 35.

Current diagnoses of fetal aneuploidies often rely upon invasive tests that sample amniotic fluid or placental tissues for fetal DNA that can then be analyzed using a variety of complex and expensive methods, including full karyotyping in which the entire set of chromosomes is viewed microscopically. While highly reliable, these invasive tests may cause infections in the pregnant woman and pose as much as a 1 percent risk of miscarriage and fetal loss. Results are not available for one to two weeks, extending anxiety for families waiting for information.

The new method relies upon massively parallel sequencing of cell-free fetal DNA using a benchtop semiconductor sequencing platform (SSP) called an Ion Torrent sequencer developed by Life Technologies. Cell-free fetal DNA is genetic material from the fetus that circulates naturally and freely in the mother's bloodstream. It can be obtained through an ordinary blood draw, with SSP analysis achieved in less than four days.

To assess the SSP method, researchers tested 2,275 pregnant women. More than 500 participated in a retrospective analysis, undergoing full karyotyping to establish known chromosomal abnormalities followed by SSP testing. The remainder participated in a prospective study without prior karyotyping, and SSP testing results were then compared to karyotyping results. The sequencing and automated bioinformatics analyses were performed at iGenomics in Guangzhou, China.

"We used the retrospective study to establish the method and the prospective study to validate it," said Zhang.

In the retrospective study, the researchers found that SSP detected multiple types of chromosomal abnormality with virtually 100 percent sensitivity and specificity compared to full karyotyping.

"To our knowledge, this is the first large-scale clinical study to systematically identify chromosomal aneuploidies based on cell-free fetal DNA using SSP," said Zhang. "It provides an effective strategy for large-scale, noninvasive screenings in a clinical setting. It can be done in hospitals and outpatient clinics, more quickly and cheaply."

###

Co-authors are Can Liao, Fang Fu, Ru Li, Yong-ling Zhang, Yan-mei Ou, Jian Li and Dong-zhi Li, Guangzhou Medical University, China; Ai-hua Yi, Jie-xia Yang, Jing Wu, Ming-qin Mai and Xiao-zhuang Zhang, Guangdong Women and Children Hospital, China; Chun-fang Peng, Yang-yi Chen, Dong-hong Luo and Hai-liang Liu, iGenomics Co., Guangzhou, China; Rui Hou, Guangzhou Kang Rui Biological Pharmaceutical Technology Co, Guangzhou, China; Frances Wu, UCSD Institute for Genomic Medicine and UCSD Department of Ophthalmology; and Hongrong Luo, UCSD Institute for Genomic Medicine and UCSD Department of Ophthalmology and Sichuan University, China.

Funding for this research came, in part, from the National Natural Science Foundation of China, National Science Foundation for Young Scholars of China, National Natural Science Foundation of Guangdong, Key Project of Guangzhou Health Bureau, Major Project of Guangzhou Science and Technology and Information Bureau, 973 program and Burroughs Wellcome Fund.

Scott LaFee | Eurek Alert!
Further information:
http://www.ucsd.edu

Further reports about: DNA Ophthalmology UCSD abnormalities chromosomal defects fetal invasive pregnant prenatal

More articles from Health and Medicine:

nachricht For drivers with telescopic lenses, driving experience and training affect road test results
30.03.2015 | Wolters Kluwer Health

nachricht Precocious GEM: Shape-shifting sensor can report conditions from deep in the body
30.03.2015 | National Institute of Standards and Technology (NIST)

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

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

Im Focus: Experiment Provides the Best Look Yet at 'Warm Dense Matter' at Cores of Giant Planets

In an experiment at the Department of Energy's SLAC National Accelerator Laboratory, scientists precisely measured the temperature and structure of aluminum as...

Im Focus: Energy-autonomous and wireless monitoring protects marine gearboxes

The IPH presents a solution at HANNOVER MESSE 2015 to make ship traffic more reliable while decreasing the maintenance costs at the same time. In cooperation with project partners, the research institute from Hannover, Germany, has developed a sensor system which continuously monitors the condition of the marine gearbox, thus preventing breakdowns. Special feature: the monitoring system works wirelessly and energy-autonomously. The required electrical power is generated where it is needed – directly at the sensor.

As well as cars need to be certified regularly (in Germany by the TÜV – Technical Inspection Association), ships need to be inspected – if the powertrain stops...

Im Focus: 3-D satellite, GPS earthquake maps isolate impacts in real time

Method produced by UI researcher could improve reaction time to deadly, expensive quakes

When an earthquake hits, the faster first responders can get to an impacted area, the more likely infrastructure--and lives--can be saved.

Im Focus: Atlantic Ocean overturning found to slow down already today

The Atlantic overturning is one of Earth’s most important heat transport systems, pumping warm water northwards and cold water southwards. Also known as the Gulf Stream system, it is responsible for the mild climate in northwestern Europe. 

Scientists now found evidence for a slowdown of the overturning – multiple lines of observation suggest that in recent decades, the current system has been...

Im Focus: Robot inspects concrete garage floors and bridge roadways for damage

Because they are regularly subjected to heavy vehicle traffic, emissions, moisture and salt, above- and underground parking garages, as well as bridges, frequently experience large areas of corrosion. Most inspection systems to date have only been capable of inspecting smaller surface areas.

From April 13 to April 17 at the Hannover Messe (hall 2, exhibit booth C16), engineers from the Fraunhofer Institute for Nondestructive Testing IZFP will be...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

World Conference On Regenerative Medicine 2015: Registration And Abstract Submission Now Open

25.03.2015 | Event News

University presidents from all over the world meet in Hamburg

19.03.2015 | Event News

10. CeBiTec Symposium zum Big Data-Problem

17.03.2015 | Event News

 
Latest News

BLS Cargo orders 15 multisystem locomotives

30.03.2015 | Press release

Shark Tagged by NSU’s Guy Harvey Research Institute Is Apparently Enjoying Time in Warm, Tropical Waters

30.03.2015 | Life Sciences

Antarctic Ice Shelves Rapidly Thinning

30.03.2015 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>