Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Gene variation makes alcoholism less likely in some survivors of sexual abuse

03.02.2010
Exposure to severe stress early in life increases the risk of alcohol and drug addiction. Yet surprisingly, some adults sexually abused as children — and therefore at high risk for alcohol problems — carry gene variants that protect them from heavy drinking and its effects, according to researchers at Washington University School of Medicine in St. Louis.

The researchers, from the university’s Midwest Alcoholism Research Center, say the finding could aid the development of therapies for alcohol dependence by offering suggestions for targeted treatments based on genetic traits and history of exposure to severe stressors.

Scientists estimate that about half the risk for alcoholism is encoded in a person’s genes. The rest comes from environmental factors, such as age at first drink and exposure to extreme stress. Other research has suggested that when the environmental risk factors occur during key periods of brain development, genes and environment working together can increase the likelihood an individual will become alcohol dependent. Child sexual abuse is one of the environmental stressors that can interact with genes to significantly increase the risk for alcohol problems.

But the researchers report in the January issue of Addiction Biology that people with a particular pattern of genetic markers seem to be protected against alcohol problems, even if they were sexually abused as children.

Those who were protected carry a set of genetic variations that scientists call the H2 haplotype. Similar to a blood type, a haplotype is more than just a single genetic mutation. It is a normally occurring pattern of gene variants that are statistically associated with one another so that when scientists find a few genetic markers, they can successfully predict what other genetic variations will occur within a particular region of DNA.

“We looked at how genes and environment interact,” says Elliot C. Nelson, M.D., lead author of the study. “Our analysis included both sexual abuse and information about the DNA region that carries the H2 haplotype. People who carry that genetic pattern were protected against the risks for alcohol consumption and alcohol dependence typically associated with sexual abuse.”

Other sexual abuse victims in the study had the alternate genetic pattern known as the H1 haplotype. Those individuals had three times the risk of heavy drinking and alcohol dependence as those who had not been sexually abused.

“They drank much more alcohol and had a significantly greater risk for problems,” says Nelson, an associate professor of psychiatry. “But abuse victims with the H2 haplotype seemed to be completely protected against those risks.”

Nelson’s team studied data from more than 1,100 people in 476 Australian families who participated in the Nicotine Addiction Genetics project. Originally, that study was set up to learn about nicotine addiction, but investigators also looked at related problems, including how much alcohol people drank and whether they met the diagnostic criteria for alcohol dependence.

Study subjects also were asked about sexual abuse in childhood. A total of 121 women and 35 men reported a history of sexual abuse beginning at around age 11. Nelson’s group also had access to DNA samples from those evaluated in this study.

By identifying a handful of specific sites in the genome, it’s possible to classify a person as having either the H1 or the H2 haplotype. One of the genes in the DNA region included in H1 and H2 is called corticotropin releasing hormone receptor type 1 (CRHR1). Nelson’s group is focusing on that gene, which research in animals has implicated in risk for alcohol dependence.

Many past studies have focused on genes related to alcohol metabolism, but CRHR1 is not a metabolism gene. Nelson says it appears from animal studies, however, that the gene may be involved in risks associated with the effects of environmental stress. In the case of humans, he suspects variants of the gene may play a role in protecting against stresses caused by child sexual abuse.

“There are many different ways an individual can become alcoholic, some involving heavy genetic risks, some involving specific environmental factors, such as exposure to peers who drink heavily,” Nelson says. “This particular pathway involving CRHR1 is interesting because it seems to play an extremely important role in animal models of alcohol consumption and dependence.”

He says better understanding of how the gene works may help scientists understand the process by which people become alcoholics. As they attempt to clarify the possible role of the CRHR1 gene in protecting sexual abuse survivors from alcohol dependence, Nelson says it may be interesting to look at other severe environmental stressors that trigger alcohol use to see whether people with the H2 variation also are protected from those forms of risk.

In addition, he says drugs have been developed that block CRHR1 receptors. If it turns out that humans are responding to the same stressors and reacting via the same genetic pathway that animals do, Nelson says some of those drugs may be able to help people who are alcoholic using the same pathway that protects people with the H2 haplotype.

A panel of leading alcoholism researchers will discuss important findings from translational and other genetic research and their implications for treatment at Washington University School of Medicine during the 10th annual Guze Symposium on Alcoholism. The topic of the Feb. 18 meeting is Disentangling the Genetics of Alcoholism: Understanding Pathophysiology and Improving Treatment.

Nelson EC, Agrawal A, Pergadia ML, Wang JC, Whitfield JB, Saccone FS, Kern J, Grant JD, Schrage AJ, Rice JP, Montgomery GW, Heath AC, Goate AM, Martin NG, Madden PAF. H2 haplotype at chromosome 17q21.31 protects against childhood sexual abuse-associated risk for alcohol consumption and dependence. Addiction Biology, vol. 15 (1); pp. 1-11, Jan. 2010

doi:10.1111/j.1369-1600.2009.00181.x

This study was supported by the National Institute on Drug Abuse and the National Institute on Alcohol Abuse and Alcoholism of the National Institutes of Health, the ABMRF/Foundation for Alcohol Research and the Australian NHMRC Fellowship Scheme.

Study authors Goate, Rice, Saccone and Wang are listed as inventors on a patent held by Perlegen Sciences Inc., covering the use of certain single nucleotide polymorphisms (SNPs) in determining the diagnosis, prognosis and treatment of addiction.

Washington University School of Medicine's 2,100 employed and volunteer faculty physicians also are the medical staff of Barnes-Jewish and St. Louis Children's hospitals. The School of Medicine is one of the leading medical research, teaching and patient care institutions in the nation, currently ranked third in the nation by U.S. News & World Report. Through its affiliations with Barnes-Jewish and St. Louis Children's hospitals, the School of Medicine is linked to BJC HealthCare.

Diane Duke Williams | EurekAlert!
Further information:
http://www.wustl.edu

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Mice provide insight into genetics of autism spectrum disorders

28.06.2017 | Health and Medicine

New photoacoustic technique detects gases at parts-per-quadrillion level

28.06.2017 | Physics and Astronomy

Funding of Collaborative Research Center developing nanomaterials for cancer immunotherapy extended

28.06.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>