Addictive cocktail: Alcoholism and genetics

Research into the genetics of alcoholism has muddled along because of the complexity of the disease, but the project has led to a slew of new discoveries that may trigger more effective pharmacological solutions.

By Victoria Stagg Elliott, AMNews staff. Feb. 5, 2001.

Mapping Disease
As the results of the Human Genome Project began to shake out into clinical applications, this 2001-02 series detailed progress in the prevention and treatment of a variety of diseases and conditions -- both on the near horizon and possibilities far into the future.

Twelve years ago, the Collaborative Studies on Genetics of Alcoholism, COGA, started its hunt for candidate genes that would indicate vulnerability to the disorder. Researchers began gathering data on more than 300 families with a high rate of problem drinking, thinking they would soon find the small group of genes at fault.

But the project, funded by the National Institute on Alcohol Abuse and Alcoholism, went nowhere fast. Instead, scientists quickly discovered that the disease was even more complicated than anticipated. It is polygenic and heterogeneous, and involved numerous environmental variables.

"The end stage of alcoholism looks fairly similar, but there are many different ways to get there, so there are probably many different genetic causes," said Robert Karp, PhD, program director for genetics at NIAAA.

More than a decade later, researchers now have a better road map. They know to look on regions of chromosomes 1, 2, 7 and 11 for genes that make a person more likely to become an alcoholic. They also know to look to a region of chromosome 4 for a gene that might provide some protection against the disease.

These discoveries have been made only recently, sped along in part because of the Human Genome Project. Now, a specific gene linked to alcoholism may be announced before year's end.

"The Human Genome Project makes searching much easier than before," said Henri Begleiter, MD, the lead researcher of COGA and a professor of psychiatry with the College of Medicine at the State University of New York in Brooklyn. "COGA for a while was floundering. We had difficulties with a number of chromosomes where genes had not been placed. And now, as we better understand the genome, we are getting very close to finding something of interest." [...]