The separate locations of these linkage signals may reflect differences in the underlying etiology across distinct populations, a suggestion supported by the observation of genome-wide significant linkage of alcohol dependence with markers on human chromosome 10 in an African American sample (47). Alternatively, this difference could reflect the inability of this kind of linkage study to accurately pinpoint the location of the gene(s) underlying a signal, or could mean that one or more of these linkage regions is associated with a false-positive signal.
