From a genetic predisposition to an interactive predisposition: rethinking the ethical implications of screening for gene-environment interactions.

In a widely acclaimed study from 2002, researchers found a case of gene-environment interaction for a gene controlling neuroenzymatic activity (low vs. high), exposure to childhood maltreatment, and antisocial personality disorder (ASPD). Cases of gene-environment interaction are generally characterized as evincing a genetic predisposition; for example, individuals with low neuroenzymatic activity are generally characterized as having a genetic predisposition to ASPD. I first argue that the concept of a genetic predisposition fundamentally misconstrues these cases of gene-environment interaction. This misconstrual will be diagnosed, and then a new concept--interactive predisposition--will be introduced. I then show how this conceptual shift reconfigures old questions and raises new questions for genetic screening. Attempts to screen embryos or fetuses for the gene associated with low neuroenzymatic activity with an eye toward selecting against the low-activity variant fall prey to the myth of pre-environmental prediction; attempts to screen newborns for the gene associated with low neuroenzymatic activity with an eye toward early intervention will have to face the interventionist's dilemma.