Other studies in rodents have demonstrated that exposure to severe, early life stressors results in epigenetically-mediated alterations in gene expression (Weaver et al. 2004; Weaver et al. 2005; Champagne et al. 2006; Weaver et al. 2007). Although admittedly speculative at present, it is possible that the protective effect which we observed could result from one or more functional polymorphisms limiting CSA-related epigenetically-mediated changes. Epigenetic modifications of gene expression due to ethanol are known to occur through a variety of different mechanisms (Pandey et al. 2008; Pietrzykowski et al. 2008; Shukla et al. 2008) and thus might not be susceptible to a similar protective effect (consistent with the lack of a significant main effect for H2 haplotype in our sample).
