This study has several advantages over related analyses, most notably the use of a national sample and identification of a relatively large number of individuals carrying the XL allele (N=89). Nevertheless, we have limited statistical power to examine some of the interactions of interest or to consider each of the observed genotypes. Although we found no evidence of gene-environment correlation (rGE) for this specific genotype-exposure combination, it remains possible that exposure to trauma is influenced by unmeasured genetic differences and that part of our estimated GxE effect could be the result of GxG interactions.
