Public Health Perspective

Medicine, 2035: The Rise of Personalized Medicine

By JAMES YARMOLINSKY

Imagine if shortly after each child is born, once all their vital signs have been assessed and their health deemed normal, a nurse takes a small blood sample from them. Imagine if this blood sample was then sent a few floors down in the hospital to a team of genetic technologists so that the genetic material in this sample, the DNA, could be separated then fully sequenced and analyzed. The results from this sequencing, ready by the end of the day, are then sent to their family doctor. Imagine if a few weeks later, at their first medical check-up, the physician already had an idea of the child’s unique genetic predisposition toward developing diseases such as cardiovascular disease, breast cancer, or type 2 diabetes, later in life. Although the expression of these diseases would still be far away, and in no way definite, their doctor will from that point forward tailor and prioritize the health education messages she suggests to the individual so to reduce the future likelihood of these diseases being expressed as much as possible. Sound like science fiction?

The above scenario is more or less what the concept of Personalized Medicine proposes. Genetic mapping has come a long way since the first draft of the human genome was completed in April 2003. Today, this successful mapping has taken us from having only a handful of diseases mapped out on genes to the discovery of more than 1800 genes associated with human disease. This isn’t just a sophisticated science experiment either, a full sequencing of your genome can be done for less than $10 000 and as this cost continues to decline, real world applications are becoming increasingly more feasible. Personalized Medicine, or Genomic Medicine, suggests a revolutionary change in the way that physicians would treat patients. Instead of viewing each patient as more or less the same, aside from variables like sex or, age, in proposing treatments for them, Personalized Medicine seeks to provide a unique tailored medical prescription based on an individual’s genetic make-up. Presently, we already have a tool that is comparable to this. Doctors will routinely ask patients about their family history of disease. With genomic sequencing however, we can bypass information shortage on the patient side and ambiguity regarding the relative contribution of parental genes and the shared environments and health behaviours that may contribute to familial disease. Instead, we have precise information on the presence or absence of individual or multiple genes within an individual that we know are linked with disease. With these genetic maps, doctors have the potential to predict their patients’ future health, or sickness.

Let’s be clear however that having access to an individuals’ genetic information pertaining to disease is not a panacea in any way. Ultimately, disease expression for most diseases arises from a unique combination of not only genetic predispositions, but also environments, social circumstances, and health behaviours. At present, we also have far more knowledge surrounding diseases associated with single genes and a general lack of information on more complex diseases like cardiovascular disease and various cancers where multiple genes are believed to be involved. Additionally, knowing an individual’s relative risks for disease will only tell us in which direction to tailor their healthcare and not with any certainty which diseases they will go on to develop. Still, this technology is potentially a major step forward.

What would the advent of routinized genomic medicine mean in terms of the role of the healthcare system? Most obviously, this would likely crucially shift healthcare from a treatment-focused system to a prevention-heavy system. Medically and ethically this can only be seen as progress. What’s not immediately clear is what the relative costs of such a system would be. On one hand, it could be predicted that costs would go down. Individuals being more aware of their genetic predisposition toward certain health problems could presumably be more likely to engage in appropriate preventive behaviours to prevent disease onset. However, this takes an optimistic perspective that individuals, once enlightened on their genetic risks for disease and armed with counteractive regimens will take a proactive approach in warding off health problems before they appear.  Additionally, what if your doctor told you that you do not have a strong disposition toward heart disease or diabetes or any other disease for that matter? Would you then be significantly less keen to monitor your diet, exercise, or reduce your sun exposure?  Similarly, there is the very real risk that individuals, through a misunderstanding of genetics, could accept a genetic deterministic view toward their own health which could have devastating effects on their consequent health behaviours. If you think that your “bad genes” giving you a higher predisposition to lung cancer are a death sentence, then why the hell not smoke, as you will surely die of lung cancer anyway?

There are also a number of other negative consequences that could arise from using this type of technology in addition to unpredictable patient reactions, namely using this technology to select out the genetically weak. Insurance companies may utilise the information to select only the healthiest people genetically to insure in their schemes, employers may ask for access to your genome before hiring you to minimise the number of sick days of their employees, and potential spouses seeking marriage and children may want to know if you have any unwanted genetic material.

The question also arises as to whether it is even ethical in the first place for governments or other institutions to take DNA samples from young children and if personalized medicine poses a threat to individual liberties and freedoms? Is it even ethical for parents to know this information given that it usually only concerns a child’s health after they have reached adulthood?

There is no doubt that with the tremendous advances being made in genomics and medical sciences, the nature of medicine is going to change. Personalized medicine is, in its truest sense, inherently a form of preventive medicine. Thus, through the adoption of personalized medicine, healthcare will move closer to what we in public health have long believed: focusing on prevention now is better than focusing on treatment later. For this reason, we must approach future exploration of personalized medicine with a sense of optimism, but also with a deep sense of caution. We are exploring medicine from a perspective only dreamed of until now.

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