Researchers have used several approaches in trying to identify the genes that influence the susceptibility to a disease, such as alcoholism. One such approach is to study whether an association exists between certain genes that are suspected (based on results of other studies) to play a role in disease development (i.e., candidate genes) and actual disease development. Such association studies evaluate whether a particular form or variant of a candidate gene is more frequently observed in people with the disease than in people without the disease (i.e., control subjects). This association implies that the candidate gene is directly involved in the development of the disease and is “linked” in genetic studies.
