What is pharmacogenomics?

 

What is pharmacogenetics and what is pharmacogenomics?

The terms pharmacogenetics and pharmacogenomics are frequently used in personalized medicine literature. While there is no definitive consensus on their definitions, there are certain features of each field that are both distinct and overlapping. Pharmacogenomics is a term introduced in late 1990s and is broadly defined as a field of study on variability in therapeutic and toxic effects of drugs using information from the entire genome of an individual. Person-to-person variations in both gene sequence and gene expression are considered in pharmacogenomics studies. By contrast, the term pharmacogenetics has been established since 1950s and refers to investigations on specific candidate genes in relation to individual differences in drug side effects and effectiveness.

Candidate genes in pharmacogenetics studies are selected based on established or postulated mechanisms of disease susceptibility, drug absorption, metabolism, transport and excretion as well as knowledge of drug targets (the cellular or extracellular molecules which bind drugs and play a pivotal role in producing the clinically observable drug effects). On the other hand, pharmacogenomics adopts a broader genome-wide and hypothesis-free approach.

Despite these notable differences, there is also interdependency between the two fields. Once the genes or genetic markers relevant to mechanism of drug action or side effects are identified through the genome-wide pharmacogenomics search, each individual gene requires further clinical validation by focused and hypothesis-driven pharmacogenetics approaches before they can be routinely applied at point of care in the clinic. We herein chose to use the term pharmacogenomics but many of the ensuing discussion and concepts on this website will also be applicable to pharmacogenetics.

 

Modified from Ozdemir and Lerer (2005) "Pharmacogenomics and the promise of personalized medicine". In: Pharmacogenomics, Second Expanded Edition. Kalow W, Meyer UA, Tyndale RF (Editors), Francis & Taylor: New York, pp. 13-50.

 

Selected bibliography

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Ozdemir, V., Kalow, W., Tothfalusi, L., Bertilsson, L., Endrenyi, L., Graham, J.E. (2005) "Multigenic control of drug response and regulatory decision-making in pharmacogenomics: The need for an upper-bound estimate of genetic contributions" Curr Pharmacogenomics Person Med 3, 53-71.

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