Pharmacogenomics refers to the use of genetic sequence data to help guide the development, selection, and dosing of medications. To date, there are relatively few examples of using genetic testing routinely in the selection or dosing of pediatric drugs; however, one classic example is testing for variations in the TPMT gene to avoid thiopurine toxicity in cancer patients.47 With time, it is likely that an increasing number of drugs will be selected and dosed based on genetic sequence information in pediatric patients. Such advances should dramatically affect pediatric oncology practice, mirroring the situation in adult cancer care. A growing understanding of the molecular basis of both common and rare conditions is having a dramatic affect on the drug development process; in conditions like cystic fibrosis molecularly targeted small molecule therapeutics specific for certain mutations are already a clinical reality.48
