Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New genetic ‘fishing net’ harvests elusive autism gene

07.02.2003


Duke University Medical Center researchers have developed a new statistical genetic "fishing net" that they have cast into a sea of complex genetic data on autistic children to harvest an elusive autism gene.



Moreover, the researchers said that the success of the approach will be broadly applicable to studying genetic risk factors for other complex genetic diseases, such as hypertension, diabetes and multiple sclerosis.

In this case, the gene, which encodes part of a brain neurotransmitter docking station called the gamma-Aminobutyric Acid Receptor beta3-subunit (GABRB3), has been implicated in autism previously, but never positively linked to the disease. Their findings will be published in the March 2003 issue of the American Journal of Human Genetics and is now available on the Web at http://www.journals.uchicago.edu/AJHG/journal/issues/v72n3/024607/024607.html.


"Many research groups have been actively looking for genetic risk factors that can lead to autism, but without much success," said Margaret Pericak-Vance, Ph.D., director of the Duke Center for Human Genetics and lead investigator of the study.

Autism is the common term that encompasses an overlapping group of complex developmental disorders that are diagnosed in about one in 1,000 children under the age of 3. Each autistic child has a unique set of characteristics that affect his or her behavior, communication skills and ability to interact with others. It is the very diverse, complex nature of autism that has made it so difficult to locate distinct genetic risk factors, said Pericak-Vance.

After several genetic studies turned up only a few vague genetic clues, the research team decided a new approach was needed. Pericak-Vance hypothesized that grouping patients with similar traits together statistically might enhance the scientists’ ability to distinguish relevant genetic risk factors. To provide guidance, the scientists turned to Michael Cuccaro, Ph.D., a clinical child psychologist at Duke with extensive experience diagnosing and treating autism. Cuccaro noticed that some but not all autistic children exhibit repetitive compulsions and extreme difficulty with changes to their daily routine. This character trait -- defined by Cuccaro as "insistence on sameness" or "IS" -- helped the research team identify a subset of autism family data to study in more detail.

Researchers, led by Yujun Shao, Ph.D., a genetic epidemiologist at Duke, reorganized data collected from families in which more than one child is affected by autism and grouped together all the families that reported their autistic child had difficulty with change.

Cuccaro’s theory that autistic children could be subdivided into at least two groups gave the team of scientists from Duke and the University of South Carolina an opportunity to test a new statistical method, called "ordered subset analysis," developed by Elizabeth Hauser, Ph.D., assistant research professor of medicine at Duke. This new genetic fishing net allows scientists to sift through complex genetic data and extract genetic risk factors that affect only some of the total group.

In this case, when the researchers applied the new test only to those families whose children scored high in the IS category, they discovered a strong link to the GABRB3 gene on chromosome 15q, where no such link had appeared before.

"This is the first successful application of ordered subset analysis to help us pinpoint a genetic risk factor that would be missed by looking at the larger group." said Pericak-Vance.

The researchers emphasize that this discovery is only the first step in understanding how the GABRB3 gene, or others genes in the same region of chromosome 15 might be involved in autism. Another clue may be gained from previous research that has shown the same area on chromosome 15 is just as responsible for Angelman Syndrome and Prader-Willi Syndrome -- two genetic disorders in which a subset of affected children also exhibit repetitive behavior. Additional research will be necessary to understand how defects in the GABRB3 gene might contribute to autistic disorder, and how other genes or environmental factors also play a role.

"In the short term, however, I think what this will allow us to do is encourage clinicians and researchers working with autistic children to think about autism as consisting of different types or subgroups and not a one-dimensional disorder," said Cuccaro. "I think that subgrouping, over time, will allow us to develop a better understanding of how to treat each individual with autism."

This is a case, said Cuccaro, where identifying subsets of patients based on clinical observations has resulted in a significant neurobiological finding, and it perhaps is pointing a way to bring clinical observations to bear on complex genetic problems.

"The genomic revolution has given us a tremendous wealth of information in terms of a road map and markers for finding disease genes," said Pericak-Vance. "Now, we need to be able to look at complex clinical information and come up with methods that can help us dissect diseases that have multiple risk factors. This new statistical test will allow us to find meaningful genetic risk factors that are diluted out when tested as part of a larger heterogeneous group."


Members of the research team also included Marissa Menold, Chantelle Wolpert, Leigh Elston, Karen Decena, Shannon Donnelly, Robert DeLong, M.D., and John Gilbert, Ph.D., of Duke; and Sarah Ravan, Ruth Abramson and Harry Wright, M.D., of the W.S. Hall Psychiatric Institute at the University of South Carolina. The research was supported by grants from the National Institutes of Health and the National Alliance of Autism Research.

Richard Puff | EurekAlert!
Further information:
http://dukemednews.org/news/article.php?id=6385
http://www.journals.uchicago.edu/AJHG/journal/issues/v72n3/024607/024607.html

More articles from Life Sciences:

nachricht Closing in on advanced prostate cancer
13.12.2017 | Institute for Research in Biomedicine (IRB Barcelona)

nachricht Visualizing single molecules in whole cells with a new spin
13.12.2017 | Wyss Institute for Biologically Inspired Engineering at Harvard

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

Im Focus: Successful Mechanical Testing of Nanowires

With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong

Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

A whole-body approach to understanding chemosensory cells

13.12.2017 | Health and Medicine

Water without windows: Capturing water vapor inside an electron microscope

13.12.2017 | Physics and Astronomy

Cellular Self-Digestion Process Triggers Autoimmune Disease

13.12.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>