Pharmacogenomics Ernie Hood Abstract
The Promise of Personalized Medicine Imagine being able to walk into your doctor's office and present a "smart card" encoded either with the sequence of your genome itself or with an access code granting permission to log on to a secure database containing your genomic information. Armed with a complete and accurate understanding of your unique genome, your physician would be able to prescribe the right drug in the right dosage at the right time to effectively treat your condition, with little or no concern that the therapy won't work or that you will suffer adverse side effects. That day of truly personalized medicine is still just a gleam in the eyes of the scientists engaged in pharmacogenomics, but they are unanimous in their belief that it is achievable and that it will arrive. Just as genomics is the study of the entire genome while genetics is the study of individual genes, pharmacogenomics looks at inheritable response to drugs over the entire genome while pharmacogenetics identifies interactions between drugs and individual genes. Pharmacogenomics seeks to uncover significant associations between genomic patterns and clinical outcomes--correlations that produce useful predictive knowledge, allowing clinical treatment decision making to be based upon more rational criteria than today's probabilistic approach, which is largely based upon educated guesswork. Drug treatment is fundamentally a well-controlled environmental challenge to the individual, says Gualberto Ruaño, vice chairman and chief scientific officer of Genaissance Pharmaceuticals in New Haven, Connecticut. "What we learn from pharmacogenomics will also apply to envirogenomics," he says, "as relates to exposures to other challenges relevant to environmental health, such as pollution, toxins, radiation, heat and cold, and even food." Although the enormous variability in people's responses to drugs cannot be attributed solely to their genotype, scientists believe that by understanding the genetic underpinnings of how people absorb and metabolize drugs, they will eventually quantify a great deal of that variability and be able to tailor therapies accordingly in order to optimize treatment and avoid adverse effects. The influential physician Sir William Osler summarized the problem aptly in 1892: "If it were not for the great variability among individuals, medicine might as well be a science and not an art." By solving much of the riddle of variability, pharmacogenomics may contribute to swinging the balance of medicine much further toward science.
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