Corporate Banner
Satellite Banner
Next Gen Sequencing
Scientific Community
 
Become a Member | Sign in
Home>News>This Article
  News
Return

Clarity Begins at Exome

Published: Friday, June 15, 2012
Last Updated: Friday, June 15, 2012
Bookmark and Share
Sequencing protein-making part of genome can change diagnosis and patient care.

In the June 13 issue of Science Translational Medicine, an international team led by researchers from the University of California, San Diego School of Medicine reports that the new technology of exome sequencing is not only a promising method for identifying disease-causing genes, but may also improve diagnoses and guide individual patient care.

In exome sequencing, researchers selectively and simultaneously target and map all of the portions of the genome where exons reside. Exons are short, critical sequences of DNA in genes that are translated into proteins – the biological workhorses involved in virtually every cellular function, plus various structural or mechanical duties.

The researchers, headed by principal investigator Joseph G. Gleeson, MD, professor of neurosciences and pediatrics at UC San Diego and Rady Children’s Hospital-San Diego, sequenced the exomes of 118 patients who had been diagnosed with specific neurodevelopmental diseases. In each of the cases, all known genetic causes of their disease had been previously excluded.

Not surprisingly, the scientists found that exome sequencing newly identified numerous disease-causing genes, including the identification of the EXOC8 gene as a cause of Joubert syndrome, a condition affecting the developing cerebellum, and GFM2 as a cause for a condition that results in a small brain combined with pediatric diabetes.

More surprising, the researchers discovered that in approximately 10 percent of cases, exome sequencing led to the identification of a known disease-causing gene, prompting a change in diagnosis and care for some patients.

“Initially, we were surprised to find mutations in genes already known to cause human disease, because we had previously excluded the known causes based upon the patient diagnosis,” said Gleeson.  “When we went back to the patients to figure out what had happened, we determined that, in each case, the original diagnosis did not agree with the genetic diagnosis. This happened in about 10 percent of the cases we studied, even though the patients had been diagnosed according to standard clinical practice.”

In each case, the researchers determined that the genetic diagnosis was fully correct, and by careful review of the patient record, determined that the original diagnosis was incorrect. “If we extrapolate these results to the general population seen in these clinics, we can infer that a large number of patients could possibly have their diagnosis and treatment modified by advanced genetic testing.”

Gleeson said the reason for these inconsistencies were manifold, but did not reflect errors in medical diagnosis – at least none that the research team could identify.  Instead, he said the differences highlight the inherent difficulty of achieving specific diagnoses, particularly given the complexities of brain development and function.

Tracy Dixon-Salazar, PhD, a member of Gleeson’s lab and first author of the study, said the findings provide proof that exome sequencing in the clinic can be a valuable tool for diagnosing disease, especially in patients like those with neurodevelopmental disorders where the prognosis is poor and treatments are limited.


Further Information
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 2,400+ scientific posters on ePosters
  • More than 3,700+ 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.


Scientific News
DNA Damage Seen in Patients Undergoing CT Scanning
Along with the burgeoning use of advanced medical imaging tests over the past decade have come rising public health concerns about possible links between low-dose radiation and cancer.
Web App Helps Researchers Explore Cancer Genetics
Brown University computer scientists have developed a new interactive tool to help researchers and clinicians explore the genetic underpinnings of cancer.
New Research Advances Genetic Studies in Wildlife Conservation
‘Next-gen’ DNA sequencing of non-invasively collected hair expands field of conservation genetics.
Gene Testing Now Allows Precision Medicine for Thoracic Aneurysms
Researchers at the Aortic Institute at Yale have tested the genomes of more than 100 patients with thoracic aortic aneurysms, a potentially lethal condition, and provided genetically personalized care.
OGT’s Popular ESHG Workshop Free to View Online
Learn about the next generation of microarrays in one of the best attended workshops of the conference.
Discordant NIPT Test Results May Reflect Presence of Maternal Cancer
Results published in Journal of the American Medical Association.
Sperm RNA Test May Improve Evaluation of Male Infertility
To help resolve uncertainty—and guide prospective parents to the right fertility treatments—scientists propose the use of a new kind of fertility test. It involves examining sperm RNA by means of next-generation sequencing.
How the Mammoth Got its Wool
Evolutionary change in a gene reconstructed in the lab from the woolly mammoth was part of a suite of adaptations that allowed the mammoth to survive in harsh arctic environments, according to new research.
NuGEN Scientists Screen 400+ Genes for Fusion Events in Single Assay
Breakthrough proves efficacy of new sample preparation method that could accelerate cancer research and development of treatments and diagnostic tests.
More Accurate and Comprehensive Whole Genome Assembly
Scientists from the Icahn School of Medicine at Mount Sinai have developed a new approach to build nearly complete genomes by combining high-throughput DNA sequencing with genome mapping.
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
2,400+ scientific and medical posters
A library of 2,500+ scientific videos on LabTube
3,700+ scientific videos
Close
Premium CrownJOIN TECHNOLOGY NETWORKS PREMIUM FREE!