Scientists identify gene that influences alcohol consumption

A variant of a gene involved in communication among brain cells has a direct influence on alcohol consumption in mice, according to a new study by scientists supported by the National Institute on Alcohol Abuse and Alcoholism (NIAAA), part of the National Institutes of Health (NIH), and the U.S. Army.

Scientists do not know yet whether a similar gene variant, with a similar effect on alcohol consumption, exists in humans.

Known as Grm7, the gene encodes a receptor subtype that inhibits the release of glutamate and other neurotransmitter molecules that brain cells use to communicate with one another. Researchers identified a gene variant, or polymorphism, that reduces the abundance of Grm7 messenger RNA (mRNA) in brain tissue. mRNA is the molecular intermediate between a gene and its protein product. Mice that possess this gene variant drink more alcohol than do mice with higher brain levels of Grm7 mRNA. A report of the study appears as an online Article in Press in Genomics.

“This is a noteworthy contribution, particularly since identifying genes that predispose to alcohol-related behaviors is such an arduous task,” says NIAAA Director Ting-Kai Li, M.D.

Scientists have long known that genes account for a significant proportion of the risk for alcoholism. However, the fact that there are multiple such genes that interact with each other and with multiple environmental factors to influence drinking behavior has hampered studies aimed at isolating individual genes.

“Controlling for this background noise -- the various gene-gene and gene-environment interactions -- presents considerable methodological challenges,” notes first author Csaba Vadasz, Ph.D., professor of psychiatric research in the department of psychiatry at New York University School of Medicine, and Director of the NeuroBehavioral Genetic Research Program at the Nathan Kline Institute in Orangeburg, N.Y.

To overcome these difficulties, Dr. Vadasz and colleagues applied a variety of genetic and analytic techniques to animals having nearly identical genetic background, but differing in their preference for alcohol, to identify a chromosomal region, and ultimately the Grm7 gene, associated with alcohol preference.

“Our findings support emerging evidence of the critical role that the brain’s glutamate pathways play in addiction,” says Dr. Vadasz. “While dopamine has traditionally been cast as a central actor in the neurochemistry of substance use and abuse, recent studies indicate that glutamate systems play an important role in reinforcement and addiction.”

If further studies show that a similar gene variant is relevant to alcohol problems in humans, the finding by Dr. Vadasz and colleagues may lead to new opportunities for developing drugs to treat alcohol dependence. Dr. Vadasz speculates that such drugs might be designed to control the level of the Grm7 gene product or modulate the activity of the gene product itself.

Source: National Institute on Alcohol Abuse and Alcoholism

Related stories:

Does Gene Variant Make Women More Prone to Alcoholism?
A particular gene variant might make women more susceptible to alcoholism. At least, a study carried out by the Universities of Bonn and Sweden’s Karolinska Institute makes this a plausible conclusion.
In Poland, Chopin's heart may hold secret of his death
The heart of Frederic Chopin, one of the world's most cherished musical geniuses, could hold the secret to his untimely death.
Oral cancers linked to genes as well as lifestyle
A major international study published today in Nature Genetics provides the strongest evidence to date that genetics play a role in oral cancers – and further emphasises the part alcohol plays in developing the disease.
World first discovery -- genes from extinct Tasmanian tiger function in a mouse
Researchers from the University of Melbourne, Australia, and the University of Texas, USA, have extracted genes from the extinct Tasmanian tiger (thylacine), inserted it into a mouse and observed a biological function – this is a world first for the use of the DNA of an extinct species to induce a functional response in another living organism.
Genetic variation linked to sugary food
A new study released today in the online edition of Physiological Genomics finds that individuals with a specific genetic variation consistently consume more sugary foods. The study offers the first evidence of the role that a variation in the GLUT2 gene – a gene that controls sugar entry into the cells – has on sugar intake, and may help explain individual preferences for foods high in sugar.
Study Describes Mechanism Linking Alcohol with Risk of Breast Cancer
The known association of alcohol consumption with an increased risk of breast cancer has been linked by researchers at the University at Buffalo to a process that causes genes that promote normal cell growth to produce proteins that precipitate unregulated cell growth, an action known as hypermethylation.
Gene therapy reduces cocaine use in rats
Researchers at the U.S. Department of Energy's Brookhaven National Laboratory have shown that increasing the brain level of receptors for dopamine, a pleasure-related chemical, can reduce use of cocaine by 75 percent in rats trained to self-administer it. Earlier research by this team had similar findings for alcohol intake. Treatments that increase levels of these chemicals - dopamine D2 receptors -- may prove useful in treating addiction, according to the authors. The study will be published online April 16 and will appear in the July 2008 issue of Synapse.
Scientists find genetic factor in stress response variability
Inherited variations in the amount of an innate anxiety-reducing molecule help explain why some people can withstand stress better than others, according to a new study led by researchers at the National Institute on Alcohol Abuse and Alcoholism (NIAAA), part of the National Institutes of Health (NIH).

News discussion:

Medicine & Health news