Table 1 Defining common tools used to deliver precision medicine

The key technologies driving Precision Medicine involve applying assays and tests that emerged from the research field in molecular biology. They include high-volume sequencing platforms (such as Illumina “next-generation” sequencing), but are not limited to that. Approaches can test for many levels of the molecular biological milieu, including the DNA (i.e. heritable “information” housed in the nucleus), RNA (i.e. the conversion of DNA information into molecules that permeate the cell and are used to construct functional proteins), proteins (i.e. the primary functional molecules of the cell), lipids and metabolites (i.e. other important molecular components of the cell). We briefly define those testing areas here, but emphasize the outsized importance of DNA-based assessments (which are typically needed in order to inform all other levels of evaluation)

Genomics—The assessment of the complete repertoire of heritable DNA; with few exceptions (e.g. cancer), results will be consistent across all cells in one’s body and over time

Exomics—The assessment specifically of the “expressed” sub-set of DNA (estimated at ~ 2% of the whole genome). While this is not as complete as a genomic test, the majority of known disease-causing variation is found in expressed regions, so this is a common economical tool in precision medicine. As with genomic tests, the results should be consistent across cell types and over one’s life span

Transcriptomics—The assessment of RNA, which provides indirect information about what genes are being expressed and to what level. Unlike genomic and exomic tests, these results will not be consistent across cell types in the body nor over time, and so may need to be performed many times and under acute circumstances to reveal the mechanism underlying one’s disease

Proteomics—The assessment of proteins, which provides direct information about what genes are being expressed and about the repertoire of functional molecules in the cell. As with transcriptomics, it will vary across cell types and over time. Critically, while this is a direct assay of functional molecules, it is much more expensive and difficult to perform at scale

Lipidomics—The specific assessment of lipid molecules, which can reveal issues with lipid synthesis pathways that are associated with many specific diseases. As with proteomics, these tests are more expensive and difficult to perform at scale

Metabolomics—The assessment of metabolites more broadly (which may include lipid molecules), used to assess activity of different metabolic biochemical pathways, and can reveal any functional bottlenecks that can contribute to diseases. As with Proteomic and lipidomic tests, they are much harder and more expensive to perform at scale