The PGRS presented throughout the manuscript were created using all autosomal SNPs. However, as several known alcohol metabolism genes are located on chromosome 4q23 (ADH4, ADH5, ADH6, ADH1A, ADH1B, ADH1C), a separate PGRS was calculated with chromosome 4 SNPs excluded to provide an estimate of polygenic risk for alcohol dependence that was independent of the SNPs within these loci.
