These links raise the possibility that variation in genes with roles in fatty acid metabolism or immune function could contribute to liability to alcohol problems. This possibility is bolstered by the preliminary evidence for enrichment of localization to DHS sites in monocytes: those results indicate that genes relevant to alcohol problems are actively transcribed in certain blood cells, which again suggests a role of immune response. The mechanism(s) through which these genes/variants might exert their effects is beyond the scope of the current study, though given the nature of the identified systems, one might speculate that the physiological response to ethanol exposure would be involved. Though previous research provides evidence that immune function and fatty acids are related to alcohol-related medical problems, which are typically a consequence of problem drinking, the current study raises the possibility that these systems are associated with problem drinking itself. Alcohol consumption impacts the immune system in myriad ways, with distinct effects in different tissues [55, 56]. Additional work is needed to determine whether variation in immune-related loci is causally related to alcohol consumption or impacts downstream processes (e.g., physiological responses that might increase liability to misuse).
