Personalized Medicine in the Paediatric Population: The Balance Between Pharmacogenetic Progress and Bioethics

Personalized medicine (PM) is becoming increasingly important in contemporary clinical and research scenarios. In the context of PM, pharmacogenomics and pharmacogenetics are aimed at the genetic personalization of drug response. Extrinsic and intrinsic factors may explain interindividual variability in drug response. Among such factors, age seems to specifically intervene to modulate drug response since normal developmental changes may influence the exposure-response relation. Consequently, the potential benefit of pharmacogenomics (PGx) in the paediatric population is considerable. However, many challenges still exist in incorporating PGx into clinical practice. In fact, drug prescribing in the paediatric population is often based on extrapolation from clinical trials conducted on adults as there is often a lack of paediatric data. Children are not just 'small adults', as they have their own pharmacological characteristics in terms of drug metabolism and efficacy, adverse drug reactions and toxicity. Although children might potentially benefit from such research, many ethical concerns arise at the intersection of the spheres of drug development and genetic testing. Children require particular attention because of their vulnerability both in research and the clinical applications of PGx; furthermore, children range from preterm newborns and neonates to infants and toddlers and to adolescents, thus forming a further heterogeneous target group. In this paper, we focus on some ethically relevant concerns (i.e., informed consent, stigmatization, ancillary information) that might arise as a result of the possible application of PGx tests in both paediatric practice and research.