Summary: Szyf (2013)

Szyf (2013) highlights the widely recognized, but poorly understood, concept of gene-environment interaction. Gene-environment interactions were first identified by epidemiologists who noted that a risk allele for increased lifetime risk of suffering from a disease is influenced by the particular environment an individual occurs in. The question still remains: How do genes and environments interact? Szyf (2013) provides a commentary on the report of Klengel et al. (2013) identifying the molecular mechanism of post-traumatic stress disorder (PTSD). Klengel et al. (2013) identified demethylation in the stress response regulator FKBP5 of a glucocorticoid response element that depends on both childhood trauma and the underlying allele.