Genomics

The terms genomics and genetics are often used interchangeably. Technically, genetics is the study of the unique DNA and RNA codes of individuals, whereas genomics is the technologies for dealing with groups of individuals or batches of genetic information. First used in 1986, the term genome referred to the mapping of the full sequence of mammalian genes. Since then, the usage for genomics has broadened to include the infrastructure necessary to exploit these research results.

What has enabled the widening influence of genomics research on health care has been the development of high-capacity information systems for processing genetic information on coding and sequencing and increased ability to use that information to associate clinical symptoms with the expression of individual and multiple genes. Although genotyping is currently expensive, costs per gene studied are dropping very rapidly, exhibiting the type of cost curves that have characterized microelectronics and computers. Because current disease definitions are based on signs and symptoms rather than on genetic classifications, it is likely that many current diseases will turn out to have multiple genetic variants. New gene-based classifications will make diagnosis and treatment much more specific, but the populations involved with each unique genetic variant will be much smaller. Clinical trials that failed may have done so because they involved patients with common symptoms but a mixture of genetic anomalies, not all of which would respond the same way to an experimental drug treatment. Although more focused Phase II trials based on genetic classification will require fewer participants and thus cost less, the likelihood of finding “blockbuster” drugs, drugs with very high market volume, is reduced, because of the smaller populations involved. Therefore, pharmaceutical companies may be less willing to incur the costs of developing them and achieving Drug Enforcement Administration (DEA) licensure.

Even when the genetic information is available, it is unlikely that simple genetic laws based on the presence or absence of a single gene will apply. More likely the findings will be probabilistic. For example, the presence of one variant of a gene may lead to a disease state 30% of the time. This could be because multiple gene combinations are involved in presentation of a disease or because multiple factors affect the type of and intensity of a gene's expression. The impact of genes interacts with the impact of environmental factors. One aphorism used in the biotechnology industry is that “genetics loads the gun, but environment pulls the trigger.”