To start: Background and why this is an important area to discuss?

For a minority of human disorder one genetic mutation leading to a single syndrome has been found. Developments in whole genome sequencing has meant that multiple genetic markers in a person’s genome can be detected relatively quickly and cost effectively. However, for the vast majority of common diseases and behavioural traits , the one mutation one attribute hypothesis does not hold true. Although associations can be made for genetic markers and any given disease/disorder/behaviour within large populations, at an individual level most are extremely poor discriminators. Furthermore, deregulation of gene expression can be due to multiple epigenetic events simply undetected by DNA sequencing. Although transcriptomics has attempted to address this deficit - clinically this requires invasive disease tissue sampling, is time consuming, costly and far more complex than originally believed; with the genome/epi-genome to disease phenotype being lost when mechanisms prevent aberrant mRNAs from being translated.

Expressed phenotypic markers are much better clinical indicators of disease status than genetic susceptibility tests. Many disorders are multi-factorial and consequently multiple different markers are measured; but one at a time. This is time consuming and costly by conventional clinical chemistry technologies.

Emerging, spectroscopic technologies can measure multiple phenotypic marker, or changes in these phenotypic markers, simultaneously: be it lipids, metabolites, blood proteins, antibodies or viral particles. With small sample volume and astonishingly fast analysis times these techniques are set to make enormous advances in diagnostic medicine. Clinical mass spectrometry is one such technique which is rapidly being adopted as a new analytical tool in laboratory Medicine, followed by NMR and Raman spectroscopy. To be fully accepted as diagnostic sample test platforms the new approaches require new standards of operating and new understanding - getting it right will hold great rewards.