Corporate Banner
Satellite Banner
Technology
Networks
Scientific Communities
 
Become a Member | Sign in
Home>News>This Article
  News
Return

Microarray Analysis Improves Prenatal Diagnosis

Published: Tuesday, November 29, 2011
Last Updated: Tuesday, November 29, 2011
Bookmark and Share
A "chip" or array that can quickly detect disorders such as Down syndrome, or other diseases associated with chromosomal abnormalities, has proved an effective tool in prenatal diagnosis in 300 cases, as reported by Baylor College of Medicine.

In the report, a team led by Dr. Arthur Beaudet and Dr. Sau Wai Cheung at BCM, described use of array comparative genomic hybridization to analyze samples taken during amniocentesis or chorionic villus sampling for chromosomal abnormalities. Amniocentesis and chorionic villus sampling allow researchers to obtain fetal cells for testing.

"Larger studies of this test will help us decide whether it should be used as a first line measure to detect chromosome abnormalities in fetuses," said Beaudet, chair of molecular and human genetics at BCM and senior author of the report. "They will also enable us to determine whether such testing should be offered more widely to pregnant women."

Cheung is professor of molecular and human genetics at BCM and director of the College's Cytogenetics Laboratory.

"The array enables you to detect smaller deletions or duplications of genetic material that would not be seen on a regular karyotype (a depiction of the size, shape and number of chromosome and any abnormalities in them)," said Dr. Ignatia B. Van den Veyver, associate professor of obstetrics and gynecology and molecular and human genetics at BCM and first author of the report. Each of these deletions or duplications is rare but added together, the rate of event could be as high as that seen in Down Syndrome.

In some of these cases where small amounts of DNA are lost or duplicated, children often have significant learning disabilities or health problems that could not be picked up with an ultrasound or other means of prenatal diagnosis, she said.

"This test adds information we could not detect by any other means right now in prenatal diagnosis," she said.

Array comparative genomic hybridization provides the tools to scan fetal DNA quickly and automatically to identify copy number variation, which indicates the deletion or addition of genetic material at a particular point on the genome.

The array starts with single-stranded fragments of DNA embedded on a glass slide to form the array, which is then exposed to fluorescently labeled single-stranded DNA. Half of the labeled DNA is from the fetus being tested and is labeled with one fluorescent color. The other is reference DNA, which is labeled with another color. The fluorescently labeled DNA – reference and patient – binds to DNA on the array. The color of the fragments will vary based on how much DNA from each binds to the DNA on the array. If the fetus has a DNA duplication, then the patient color on the array will be stronger. If the fetus has a deletion, the reference color will show up stronger. A specialized scanner evaluates the color differences, which are then fed into a computer for analysis.

In this study, most of the women sought prenatal testing because they were older and faced a higher risk of having children with certain chromosomal abnormalities, such as Down syndrome. Some had had abnormal ultrasounds and needed more information, and still others had had children with a genetic abnormality previously.

The scientists found 58 copy number variations, which indicate that there is either more or less genetic material than one would expect to find at that location on the chromosome.
Forty of these variations were interpreted as benign. Thirty-nine of them were inherited from a parent who had no evidence of genetic disease. One had been seen before and had not been associated with disease.

In 15 cases when the array detected something that was significant for patient care, the finding was either suspected because the mother "carried" the change in her DNA, or because another prior test, such as a karyotype, had detected it.

Three cases were classified as uncertain. Two of these involved copy number variations, not seen before and not inherited from the parents, in fetuses with birth defects identified on the prenatal ultrasound. In one, the array findings were interpreted as likely unrelated to the birth defects and in the other they were thought to cause the defects. In the third case, there was a relatively large deletion in an area of chromosome 3, but it was also present in the mother, who had no reported medical problems.

In two cases the array comparative genome hybridization identified disorders that would have been missed otherwise and in seven cases the results added new information about risk of disease valuable in genetic counseling.

"My conclusion is, that providing there is good genetic counseling that accompanies it, the test can be offered to prospective parents who want prenatal diagnosis. There are many parents interested in having this additional diagnostic information," said Van den Veyver. "If we use an array that is targeted and we have parental samples to confirm the meaning of detected changes, in the majority of cases, we will be able to counsel the patients about the significance of the findings."


Further Information

Join For Free

Access to this exclusive content is for Technology Networks Premium members only.

Join Technology Networks Premium for free access to:

  • Exclusive articles
  • Presentations from international conferences
  • Over 3,300+ scientific posters on ePosters
  • More Than 4,900+ scientific videos on LabTube
  • 35 community eNewsletters


Sign In



Forgotten your details? Click Here
If you are not a member you can join here

*Please note: By logging into TechnologyNetworks.com you agree to accept the use of cookies. To find out more about the cookies we use and how to delete them, see our privacy policy.

Related Content

Myeloid-Derived Suppressor Cells Play Role in Tumor Growth
Researchers at Baylor College of Medicine have reported a new mechanism that helps cancer cells engage myeloid-derived suppressor cells.
Friday, May 20, 2016
Largest Genomic Study on Kidney Cancer
Understanding the complexity of cancer is a major goal of the scientific community, and for kidney cancer researchers this goal just got closer.
Wednesday, March 16, 2016
Largest Genomic Study on Kidney Cancer Brings Hope for More Effective Treatments
Researchers at Baylor College of Medicine have found that a pathway called immune checkpoint was most active in a subtype of clear cell kidney cancer that is typically very aggressive.
Tuesday, March 08, 2016
Baylor, DNAnexus Collaborate
Partnership sets out to develop HgV, a new iteration of HGSC's Mercury, a BCM-developed data processing and variant calling pipeline for analyzing and annotating next-generation sequencing data in research and clinical contexts.
Tuesday, June 23, 2015
Baylor, TGen Collaborate on Personalized Cancer Treatment Options
The companies will collaborate on precision medicine for cancer patients by offering liquid biopsies, performing gene sequencing, conducting clinical trials, and creating personalized vaccines.
Tuesday, May 26, 2015
Role of Cancer Stem Cells in Chemo-Resistance
'Wound response' of cancer stem cells may explain chemo-resistance in bladder cancer.
Friday, December 05, 2014
Massimo Pietropaolo Named McNair Scholar at Baylor
World renowned physician-scientist in type 1 diabetes research, Dr. Massimo Pietropaolo, has been named McNair Scholar at Baylor College of Medicine.
Wednesday, October 29, 2014
Clinical Integration of NGS
Experts provide much-needed policy analysis for clinical integration of next generation sequencing.
Tuesday, September 23, 2014
Collaboration Unravels Novel Mechanism for Neurological Disorder
The novel gene (CLP1) associated with a neurological disorder affecting both the peripheral and central nervous systems.
Saturday, April 26, 2014
$3M NIH Grant Enables Baylor International HIV/AIDS Program
Researchers to study genetic differences of disease in sub-Saharan African children.
Wednesday, February 19, 2014
Baylor College of Medicine, Berry Genomics Co. Seek to Improve on Prenatal Genetic Tests
Teams aim to improve prenatal genetic testing by combining BCM’s expertise in using microarrays for DNA analysis and Berry’s non-invasive technology evaluating fetal DNA in maternal plasma.
Monday, January 07, 2013
Experimental Drug Targets Chemo-Resistant Breast Cancer Stem Cells
The cells that remain after treatment that could potentially refuel tumor growth, researchers say.
Monday, December 14, 2009
Protein 'Tubules' Free Avian Flu Virus from Immune Recognition
Two domains or portions of the protein NS1 combine to form tiny tubules where double-stranded RNA is hidden from the immune system, researchers say.
Friday, November 07, 2008
High Throughput Imaging Speeds Analysis of Hormone Receptors
A new high throughput microscopy technique enabled researchers at Baylor College of Medicine to analyze thousands of individual cells expressing androgen receptor.
Monday, November 03, 2008
Lack of Fragile X, Related Gene Disrupts Sleep
Deficiency of the FMR1 gene and a similar gene called FXR2 could account for sleep problems associated with inherited mental impairment.
Friday, June 27, 2008
Scientific News
Breakthrough Flu Vaccine Inhibited by Pre-existing Antibodies
Universal truths – how existing antibodies are sabotaging the most promising new human flu vaccines.
Researchers Develop Software That Could Facilitate Drug Development
AptaTRACE can identify aptamers, potentially speed drug advancement.
Gene Therapy for Metabolic Liver Diseases
Researchers have tested gene therapy in pigs from hereditary tyrosinemia type 1, with corrected liver cells being transplanted into the diseased liver.
Zika Vaccine Candidates Show Promise
Two experimental vaccines have shown promise against a major viral strain responsible for the Brazilian Zika outbreak.
New Medication Shows Promise Against Liver Fibrosis in Animal Studies
Liver fibrosis is a gradual scarring of the liver that puts people at risk for progressive liver disease and liver failure.
Raw Eggs Deemed Safe to Eat
A report published today by the Advisory Committee on the Microbiological Safety of Food (ACMSF) into egg safety has shown a major reduction in the risk from salmonella in UK eggs.
Monitoring TTX Toxin in Shellfish
In a number of small studies, mussels and oysters from the eastern and northern part of the Oosterschelde in Holland were found to contain tetrodotoxin (TTX).
Gene Terapy for Muscle Wasting Developed
New gene therapy could save millions of people suffering from muscle wasting disease.
NIH Begins Yellow Fever Vaccine Trial
NIH has initiated an early-stage clinical trial of a vaccine to protect against yellow fever.
Gene-Editing 'Toolbox' Targets Multiple Genes Simultaneously
Researchers have designed a system that modifies, or edits, multiple genes in a genome at once while minimising unintentional effects.
Scroll Up
Scroll Down
Skyscraper Banner

Skyscraper Banner
Go to LabTube
Go to eposters
 
Access to the latest scientific news
Exclusive articles
Upload and share your posters on ePosters
Latest presentations and webinars
View a library of 1,800+ scientific and medical posters
3,300+ scientific and medical posters
A library of 2,500+ scientific videos on LabTube
4,900+ scientific videos
Close
Premium CrownJOIN TECHNOLOGY NETWORKS PREMIUM FOR FREE!