Pharmacogenetic analysis of clinically relevant genetic polymorphisms.

The ascertainment of the human genome sequence has generated great enthusiasm for the use of gene-based approaches to improve virtually all aspects of medical care. Particular interest has focused on the field of pharmacogenetics--for example, the use of an individual's genetic profile to optimize drug prescription. This approach takes advantage of the presence of single-nucleotide polymorphisms (SNPs) or other genetic variants in every gene in the human genome. There are currently > 9 million SNPs in the human SNP database dbSNP, with an estimated 11 million variants ultimately to be found in the human population. To date, the preponderance of interest in this field has centered on the potential of applying this approach to subacute or chronic illnesses, such as cancer, cardiovascular disease, human immunodeficiency virus infection, or rheumatologic disorders. In contrast, little attention has been devoted to the potential utility of implementing the pharmacogenomic methodology for guiding drug selection for acutely ill patients in the critical care environment. Although such an approach has theoretical appeal as a means of enhancing quality and improving outcomes in this setting, several obstacles currently exist and slow the progress toward clinical application.