these ALCP-total SNPs were in strong LD (r2 ~ 0.98) with top SNPs from the EXT results. The SNP on chromosome 3 was in LD with two SNPs in the CADM2 region, while the SNP on chromosome 11 was in LD with a SNP on NCAM1. CADM2 has been implicated in previous GWAS of other substance use phenotypes [35, 36], risky behaviors [36–38], and impulsivity [38]. Overall, the SNP level results broadly point to two distinct pathways of risk: one related to risk taking/impulsivity, and one specific to the body’s processing of alcohol, both of which are entwined in the univariate GWAS results for problematic alcohol use.
