What percentage of someone's genetic background may contribute to alcohol dependency?

The percentage of an individual genetic background that may contribute to alcohol dependency is 50%.

Explanation:

Alcohol dependency refers to a chronic disease in which the affected individual has an uncontrollable urge for alcoholic drinks. There are many factors that can cause one to depend on alcohol and one's genetic background is one of them.

Recently, researchers have been able to identify a specific gene that is responsible for development of alcoholic dependency. Before now, scientific studies have been able to proof that children born by alcoholic parents have high tendency of becoming alcoholic adults. The percentage of genetic heritage that is responsible for alcoholic use is as high as 50%