Thus, the present study had three aims. First, in a sample ascertained for heterogeneous purposes, the aim was to determine whether linkage was confirmed in gene regions previously associated with alcohol-related traits. The second aim was to examine whether linkage is influenced by participant age. Finally, the effect of including light drinkers in analyses was examined by comparing full-sample results with linkage obtained using truncated samples that dropped individuals at the lower end of the consumption distribution. Linkage analyses have some limitations, not least of which is low power to detect linkage for complex traits influenced by multiple genes. Accordingly, evidence of linkage in gene regions with known associations to alcohol-related traits would be a promising finding.
