Notably, although PTSD risk in epidemiological studies is higher in women than men71, here we found no sex differences in heritability. Five loci on the X chromosome associated with the disorder. Our finding that the estrogen receptor (ESR1) gene was identified in GWAS, as well as observations of differential effects of estrogen levels on a variety PTSD symptoms,72,73 suggests the importance of further analyses of ESR1 as a potential mediator of observed sex differences.
