Comment on "Study of glucose-6-phosphate dehydrogenase: history and molecular biology," by Ernest Beutler, Am J Hematol 42:53-58, 1993

Pharmacogenetics and pharmacogenomics: origin, status, and the hope for personalized medicine

Pharmacogenetics arose with studies of single genes, which had major effects on the action of particular drugs. It turned into pharmacogenomics through realization that the controls of most drug responses are multifactorial. Then, variable gene expression posed new problems, for example what do drugs do to genes, or how useful is any genetic pretesting of a person? A common disease may be caused by different groups of genes in different people, who therefore require different drugs for treatment. Personalized medicine is currently represented by a physician's attention to a patients age, sex, or ethnic background, that is groups showing smaller genetic variation than is typical for general humanity. Occasionally, there is also the use of single-gene pretesting of a patient before drug administration. Over time, improvements in multigenic testing promise to increase the role of personalized medicine. However, the many pharmacogenomic complexities, and particularly time-dependent changes of gene expression, will never allow personalized medicine to become an error-free entity.

Human pharmacogenomics: the development of a science

Until about 50 years ago, the altering of a normal drug effect by a genetic deficiency was only rarely observed. Here, my discovery of the genetic variant of butyrylcholinesterase affecting succinylcholine action is described in some detail. Such discoveries led to the combination of the two older sciences, genetics and pharmacology, thereby forming pharmacogenetics. After the discovery of similar examples in the years that followed, pharmacogenetics expanded on the basis of two discoveries. First, the common occurrence of interethnic differences in drug response and, secondly, the fact that most pharmacological differences were multigenic. New methodologies brought a transition to pharmacogenomics; this included detection of clinically important genetic variants and has uncovered potentially new drug targets. The arrival of personalised medicine--where a patient's genes determine the choice of drug to be administered--can be hoped to gradually improve drug safety and efficacy. Efforts to reach this level of perfection are, however, dogged by uncertainties.