Genetic analyses in this subsample of the COGA dataset have implicated several different chromosomal regions as possibly containing one or more genes contributing to alcohol dependence; to related clinical characteristics (i.e., phenotypes) such as smoking, depression, suicidal behavior, conduct disorder, and the largest number of drinks within a 24-hour period; and to neurobiological endophenotypes such as event-related potentials and brain oscillations in electrophysiological activity (Edenberg 2002; Edenberg and Foroud 2006). Despite much progress, however, identification of the specific genes contributing to these phenotypes remains a challenging task because they lie within broad linkage regions that often encompassed 10 to 30 million base pairs.
