As mentioned earlier, epigenetic variation (such as DNA methylation) may be an explanation for some of the “missing heritability” of AUDs, considering that AUD-associated genetic variants identified by GWAS only explained a minority of the expected heritable fraction of AUDs.92 The findings from published studies suggest that DNA methylomic studies, when integrated with GWAS research, could uncover more of the genetic and epigenetic mechanisms of AUDs. Nevertheless, several methodological and scientific challenges in DNA methylomic studies must be addressed before fruitful results can be obtained.
