Turning to public health, our research adds a genetic dimension to long-standing arguments that early prevention could be a critical strategy in reducing cigarette consumption.66 Specifically, our findings and others’32 suggest that initiatives that disrupt the developmental progression of smoking behavior, such as surtaxes and age restrictions on tobacco purchases, may ameliorate some genetic risks.67 Moving beyond population-level prevention, we showed that information about smoking risk captured in a score composed of GWAS-identified variants was independent of information that could be derived from a family history of smoking behavior. This novel finding suggests that genetic information could be used to identify “high-risk” youngsters for targeted prevention.62,68 However, the associations we detected between the genetic risk score and smoking phenotypes were small in magnitude. Small effect sizes do not preclude public-health relevance,69 but they do caution against the use of genetic information to evaluate risk in individuals;70 children that our study would classify at high genetic risk are not guaranteed to become addicted if they try smoking and, even more importantly, children we would classify at low genetic risk are not
