To our knowledge, none of the top SNP effects identified in the previous study by Kapoor et al.15 have yet been replicated. However, the significance associated with individual top SNPs might be subject to sample-specific characteristics (for example, families densely affected for alcoholism). Recently, investigators have begun to use genome-wide risk scores (GRS) that reflect the polygenic and aggregate nature of genotypic effects. Effect sizes generated for one phenotype in a given sample can be used to generate GRS in additional samples; the association between these GRS and a similar phenotype may be seen as evidence for replication while correlations between the GRS and other related phenotypes provide support for shared genetic underpinnings.16
