DNA test that identifies Down syndrome in pregnancy can also detect trisomy 18 and trisomy 13
A newly available DNA-based prenatal blood test that can identify a pregnancy with Down syndrome can also identify two additional chromosome abnormalities: trisomy 18 (Edwards syndrome) and trisomy 13 (Patau syndrome). The test for all three defects can be offered as early as 10 weeks of pregnancy to women who have been identified as being at high risk for these abnormalities.
These are the results of an international, multicenter study published on-line today in the journal Genetics in Medicine. The study, the largest and most comprehensive done to date, adds to the documented capability (study published in Genetics in Medicine in October 2011) of the tests by examining results in 62 pregnancies with trisomy 18 and 12 pregnancies with trisomy 13. Together with the Down syndrome pregnancies reported earlier, 286 trisomic pregnancies and 1,702 normal pregnancies are included in the report.
The research was led by Glenn Palomaki, PhD, and Jacob Canick, PhD, of the Division of Medical Screening and Special Testing in the Department of Pathology and Laboratory Medicine at Women & Infants Hospital of Rhode Island and The Warren Alpert Medical School of Brown University, and included scientists at Sequenom Inc. and Sequenom Center for Molecular Medicine, San Diego, CA, and an independent academic laboratory at the University of California at Los Angeles.
The test identified 100% (59/59) of the trisomy 18 and 91.7% (11/12) of the trisomy 13 pregnancies. The associated false positive rates were 0.28 and 0.97%, respectively. Overall, testing failed to provide a clinical interpretation in 17 women (0.9%); three of these women had a trisomy 18 pregnancy. By slightly raising the definition of a positive test for chromosome 18 and 13, the detection rate remained constant, but the false positive rate could be as low as 0.1%. These findings, along with the detailed information learned from testing such a large number of samples, demonstrate that the new test will be highly effective when offered to women considering invasive testing.
"Our previous work demonstrated the ability to identify Down syndrome, the most common trisomy. These new data extend the finding to the next two most common trisomies and will allow for wider use of such testing with the ability to identify all three common trisomies," said Dr. Palomaki. "The new DNA test can now also be offered to women identified as being as high risk for trisomy 18 or trisomy 13, as well those at high risk for Down syndrome."
"This highly sensitive and specific DNA test has the potential to impact on couples' decision-making," says Dr. Canick. "A woman whose pregnancy was identified as high risk who earlier would have chosen not to have invasive diagnostic testing, might now consider the DNA test as a safe way to obtain further information, before making a final decision." The US Centers for Disease Control and Prevention estimated in 1995 that about one in every 200 invasive diagnostic procedures will cause a pregnancy miscarriage.
Trisomy 18, also called Edwards syndrome, is a serious disorder with up to 70% of first trimester affected fetuses being spontaneously lost during pregnancies. Among those born alive, half die within a week with only 5% surviving the first year. All have serious medical and developmental problems. About 1,330 infants with trisomy 18 would be born in the US each year in the absence of prenatal diagnosis. Trisomy 13, also called Patau syndrome, is less common but equally serious. About 600 infants with trisomy 13 would be born in the US each year in the absence of prenatal diagnosis. Like Down syndrome, trisomy 18 and trisomy 13 are more common as maternal age increases. For comparison, about 7,730 Down syndrome cases would be born each year in the absence of prenatal diagnosis. Current prenatal screening tests for trisomy 18 and trisomy 13 rely on both biochemical and ultrasound markers. For more information visit the US National Library of Medicine PubMed Health.
This industry-sponsored project, awarded to Drs. Palomaki and Canick and Women & Infants Hospital in 2008, enrolled 4,500 women at 27 prenatal diagnostic centers throughout the world. Women & Infants also served as one of the enrollment centers under the direction of maternal-fetal medicine specialist and director of Perinatal Genetics, Barbara O'Brien, MD.
"It is clinically more relevant that all three trisomies can be detected by this test," said Dr. O'Brien. "Having access to such a comprehensive, DNA-based test that can be done early in pregnancy will give us more information so that we can better guide which patients should consider diagnostic testing."
Provided by Women & Infants Hospital
- Study shows that new DNA test to identify Down syndrome in pregnancy is ready for clinical use Oct 17, 2011 | not rated yet | 0
- Prenatal biochemical screening only detects half of chromosomal abnormalities Jun 02, 2008 | not rated yet | 0
- Noninvasive test for trisomy 21 closer at hand Feb 10, 2011 | not rated yet | 0
- Cheap, simple, noninvasive blood test may replace invasive diagnostic techniques in early pregnancy Jun 29, 2010 | not rated yet | 0
- Down syndrome test breakthrough 'on the horizon' Mar 08, 2011 | not rated yet | 0
- Motion perception revisited: High Phi effect challenges established motion perception assumptions Apr 23, 2013 | 3 / 5 (2) | 2
- Anything you can do I can do better: Neuromolecular foundations of the superiority illusion (Update) Apr 02, 2013 | 4.5 / 5 (11) | 5
- The visual system as economist: Neural resource allocation in visual adaptation Mar 30, 2013 | 5 / 5 (2) | 9
- Separate lives: Neuronal and organismal lifespans decoupled Mar 27, 2013 | 4.9 / 5 (8) | 0
- Sizing things up: The evolutionary neurobiology of scale invariance Feb 28, 2013 | 4.8 / 5 (10) | 14
gravity is std. therefore can we rate a 'mass at height' by watts?
59 minutes ago For example.... wind turbines are primarily listed by their wattage (1.5MW etc.) Presumably their output is varied according to rotational speed, so...
Calculating on-axis elements of a solenoid
13 hours ago I wanted to mention that this solenoid has many winds over many layers. The thickness of the windings is 2.4 inches coming off of the engineering...
latitude & longitude & air pressure
14 hours ago Hi there, I have a peculiar question. Imagine that you are in a earth position, obtained by google, that gives you the latitude and longitude....
Differences of Classical Mechanics when learned with Calc vs algebra?
17 hours ago what are the differences? Every example I find usually has a derivative or integral or some kind of calculus defined concept that seems to make it...
what is the distance traveled
21 hours ago A rough sketch of experiment. Image: http://i43.tinypic.com/14t4sk5.png the red dots represent a side view of path traveled, F is downward force...
Image of a Convex Lens Cut in Half Horizontally
May 22, 2013 Hello everyone, A friend of mine came up with this question in class and I really do not have a good answer. Suppose you have a convex lens...
- More from Physics Forums - Classical Physics
More news stories
A study of around 1,000 UK mothers and their children, published in The Lancet, has revealed that iodine deficiency in pregnancy may have an adverse effect on children's mental development. The research raises concerns that t ...
Obstetrics & gynaecology May 21, 2013 | not rated yet | 0
Nearly three out of four pregnant women experience constipation, diarrhea or other bowel disorders during their pregnancies, a Loyola University Medical Center study has found.
Obstetrics & gynaecology May 20, 2013 | not rated yet | 0
New research indicates that women's reproductive function may be tied to their immune status. Previous studies have found this association in human males, but not females.
Obstetrics & gynaecology May 17, 2013 | not rated yet | 0 |
Elsevier today announced the publication of a recent study in Reproductive BioMedicine Online on 5-day old human blastocysts showing that those with an abnormal chromosomal composition can be identified by the rate at whic ...
Obstetrics & gynaecology May 16, 2013 | not rated yet | 0
While global attention has for decades been focused on reducing maternal mortality, population-based data on other causes of death among women of reproductive age has been virtually non-existent. A study conducted by researchers ...
Obstetrics & gynaecology May 14, 2013 | not rated yet | 0
(Medical Xpress)—Research by U of T Mississauga psychology professor Glenn Schellenberg reveals that two key personality traits – openness-to-experience and conscientiousness—predict better than IQ ...
55 minutes ago | not rated yet | 0 |
Professor Michael Jennings, Deputy Director of the Institute for Glycomics at Griffith University, was part of an international team that discovered the previously unknown pathway of how the bacterium colonizes people.
33 minutes ago | 5 / 5 (1) | 0 |
Scientists at Newcastle University have shed new light on how the brain tunes in to relevant information.
29 minutes ago | 5 / 5 (1) | 0 |
Aggressive forms of bladder cancer involve the protein PODXL – a discovery that could hold the key to improved treatment, according to researchers at Lund University, Uppsala University and KTH in Sweden.
1 hour ago | 5 / 5 (1) | 0
New techniques in imaging of brain activity developed by Jean Gotman, from McGill University's Montreal Neurological Institute, and his colleagues lead to improved treatment of patients suffering from epilepsy. The combination ...
30 minutes ago | not rated yet | 0
Studying the networks of connections in the brains of people affected by schizophrenia, bipolar disease or depression has allowed Dr. Peter Williamson, from Western University, to gain a better understanding of the biological ...
29 minutes ago | not rated yet | 0