Over the past several years numerous whole genome linkage studies have been performed in which the inheritance of phenotypes and genetic markers is followed in families. Two influential linkage scans, one in a Southwestern American Indian tribe45 and the other in the large, predominantly European-ancestry Collaborative Study on the Genetics of Alcoholism (COGA) dataset46 found evidence for linkage of AUD near the chromosome 4 GABAA receptor subunit gene cluster. This finding led to the discovery of the association of the GABRA2 gene with AUD, a widely replicated finding. Other more modest linkage findings for AUD and alcohol-related phenotypes in AI are comprehensively reviewed elsewhere.47
