Introduction
One of the most significant technological accomplishments in recent history was the complete sequencing of the human genome. This was a collaborative effort spanning fifteen years and involving scientists and academics from around the globe. When the first draft was published in 2003, almost two years ahead of schedule, it gave us the ability, for the first time, to read nature’s complete genetic blueprint for building a human being. It also created an expectation that with detailed knowledge of the genome would come insights into the prevention and management of disease. However, sequencing the human genome heralded only the first (major) step in this direction. The research potential that was unlocked, to identify the disease causing genes and the changes in gene expression that may initiate a disease process, has brought us much closer to the eventual implementation of precision medicine.
The Human Genome Project has helped to create a healthcare environment that is not only personalised but also predictive. One of the key drivers of the burgeoning “wellness” environment is the desire of individuals to take more responsibility for their own health. One aspect of this entails taking proactive steps to prevent disease, rather than relying on the healthcare system to cure the disease only after it manifests. Given that the massive burden of chronic disease with which we are faced is predominantly lifestyle driven, there is much that the average health-conscious individual can do to reduce this burden.
The Human Genome Project has helped to create a healthcare environment that is not only personalised but also predictive. One of the key drivers of the burgeoning “wellness” environment is the desire of individuals to take more responsibility for their own health. One aspect of this entails taking proactive steps to prevent disease, rather than relying on the healthcare system to cure the disease only after it manifests. Given that the massive burden of chronic disease with which we are faced is predominantly lifestyle driven, there is much that the average health-conscious individual can do to reduce this burden.
At the intersection of genetic testing and personalised medicine lies the understanding that recommendations given to one person on diet, nutrition and lifestyle, are not necessarily the same recommendations given to another person. We know this intuitively, as our propensity to hop from one weight loss program to another testifies. With the benefit of foresight provided by a DNA test, those days are behind us. Individuals can be informed of the most suitable diet type for weight management, the specific nutrients their bodies require for optimal cellular health, the most suitable exercise regime according to their genetic potential, and they can be empowered by this knowledge to make the most appropriate and relevant lifestyle and medical choices.
Nowhere has the advent of personalised medicine been more apparent than with the advances in the field of pharmacogenomics – a field of study that explores the relationship between genetic variations and differences in drug metabolism. The adoption of pharmacogenomics (PGx) in clinical practice promises more effective decision-making regarding drug selection and dosing,1 and offers several ways in which to individualise drug treatment, including drug selection, drug dosages, maximising effectiveness and minimising undesirable side effects.
The successful implementation of effective genetic testing as part of clinical prescribing could prove highly beneficial to the physician, the patient and the funders. The risks of adverse drug reactions (ADR) are very real. Of the 27 drugs frequently cited in ADR studies, 59% are metabolised by at least one enzyme that has a variant allele known to cause poor metabolism.3 A recent meta-analysis in the United States of America suggested that ADRs are the fourth most common cause of death.4 Reducing ADRs clearly has significant benefits for patient safety as well as to reduce the costs of further treatment or recovery.
Pharmacogenomics also provides benefits compared to current approaches to therapeutic drug monitoring. In contrast to traditional monitoring, “testing can be undertaken before treatment begins, does not require the assumption of steady state conditions (or patient compliance) for the interpretation of results, could be performed less invasively (e.g. with mouth swabs) and could provide predictive value for multiple drug substrates rather than a single drug, and would be consistent over an individual’s lifetime”
