In summary, GWASs have been limited by difficulties in quantifying alcohol-related phenotypes and in obtaining large sample sizes, together with co-morbidity of alcoholism with other behavioral and neuropsychiatric disorders, gender effects and population admixture. Furthermore, the diversity of mechanisms of vulnerability and resilience to alcohol pose challenges for human genetic studies on alcoholism or alcohol consumption. It has become increasingly clear that, in addition to a few common alleles, many different rare alleles may contribute to vulnerability in different populations.
