Researchers mapping the highway of human heredity may have found a key to alcoholism.

Their work could lead to ways of identifying youngsters most at risk of becoming alcoholics and helping them avoid that future.An estimated 14 million Americans suffer from alcoholism, and it has long been known that the problem runs in families. But it had not been clear if it was inherited or a result of environment, Dr. Enoch Gordis, director of the National Institute on Alcohol Abuse and Alcoholism, said this week.

Now, he said, researchers have concluded that inheritance plays a role and they have located likely neighborhoods for the genes that can lead to trouble.

He said further studies to locate the exact genes could lead to treatments for alcoholism, more focused prevention efforts and better understanding of the role of environment and the working of the human brain.

Genes are portions of the human chromosome, a pair of long molecules in each cell that determine the characteristics of the person.