Many variants in loci identified by GWAS are in noncoding regions, and likely to drive differences in gene expression. Behavioral responses to alcohol ingestion as well as symptoms of dependence and withdrawal are likely mediated by the central nervous system, suggesting that gene expression analyses in selected brain regions could provide insights. In fact, a number of studies, including several by COGA, 9 , 10 , 11 , 12 , 13 have compared patterns of gene expression in brain regions of individuals with and without AUD, and examined the effects of alcohol on gene expression. Comparison of gene expression in post‐mortem brain regions of individuals with and without AUD identifies differences that may be related to pre‐existing genetic risk factors or to the effects of long‐term exposure to high levels of alcohol, or both.
