Launched in 2012 by the University of Toronto and the Hospital for Sick Children, the Personal Genome Project Canada (PGP-C) is the Canadian counterpart of Harvard Medical School’s Personal Genome Project. The project aims to sequence the genomes of 100 Canadians, integrate this data with personal health care information, and make these genomes freely available to the public.
A relative of mine got extremely sick last year. They were not too old and had no major health issues prior to this. They had a sudden bout of weakness in their body and their health got increasingly worse thereafter. The doctor ordered several tests. None of them came back positive, and after a month and a half, my relative passed away.
Because the doctors were not able to find out what was afflicting them, treatment and cure were not even part of the question.
This story is heartbreaking to me on both a personal and a scientific level — was there anything more that could have been done?
DNA sequencing, or genomics, has been an important discussion in genetics and health care for the past few decades. Sequencing the human genome first came into the limelight in the early 1990s with the Human Genome Project (HGP). The HGP cost an astonishing $2.7 billion — today, sequencing a whole genome has become much more affordable at around $1,000. Lower costs have allowed us to personalize it.
PGP-C researchers anticipate that whole genome sequencing will likely become part of mainstream health care in the near future.
PGP-C integrated participants’ genomic data with their personal health information to help understand genetic contributions to human health and disease. It also gives patients direct access to their genetic information through an online database. Analysis of this genetic information can help doctors determine potential disease risks, how your body will react to certain drugs, and more.
Most importantly, genetic diseases can be revealed through this technology. Risk factors for cancer, cystic fibrosis, arthritis, and even high blood pressure can be detected through genetic testing before symptoms manifest. This kind of early detection is key for preventing and treating some of these diseases. Having more time for proper treatment can make all the difference.
Personal genomics is also an important tool for ‘precision medicine’: the tailoring of health care according to each individual. We are not all built the same, at least not genetically. Thus, different people sometimes need different treatments for the same disease.
This is why cancer treatments are often individualized. Currently, most cancer patients receive a combination of various treatments, including chemotherapy and radiation. With the help of personal genomics, doctors can give more targeted treatment to individuals based on how they might respond to a drug or therapy.
I think a lot about my relative who passed away. Had personal genomics been available, was there a chance of saving them? If the sickness was genetic in nature, perhaps we would have identified the cause. Personal genomics can help change how we see medicine and how we diagnose and treat patients. It can provide the guidance that is needed in the world of medicine today.
Anya Rakhecha is a first-year Life Sciences student.
The usefulness of personal genomics can only go as far as our understanding of the human genome. There is a significant discrepancy between an individual’s genomic information and their actual state of health: findings from PGP-C seem to indicate that people can be missing huge chunks of chromosomes without negative effects on health.
One participant, for example, possessed risk factors for aortic stenosis, a lethal heart defect that develops before birth. Yet that individual is a healthy 67-year-old who works long hours, skis, and has a normally functioning heart.
These false positives — supposedly harmful mutations in DNA with no ill effects — suggest that the accuracy of genetic testing for uncovering health issues is uncertain, at least until scientists develop the necessary tools to fully decode the human genome.
Moreover, extensive testing may provide more data, but this also runs the risk of overdiagnosis. If the results of a genetic test indicate that a patient is at risk of developing a disease, a doctor could take precautionary measures and prevent the illness from manifesting. But in the case where the disease is actually harmless or does not develop, precautionary treatments could cause more harm than good due to side effects.
The increasing accessibility of genomic information also comes with potential social consequences. Canada’s recently passed Genetic Non-Discrimination Act protects individuals from having to disclose the results of a genetic test to an employer, but the same cannot be said for health insurance.
According to the Canadian Life and Health Insurance Association’s voluntary code, results of genetic tests can be requested by companies if the application is for a premium worth $250,000 or more. Considering the privacy risks associated with having your genome accessible to third-party organizations, some people may deliberately avoid genetic testing, which means that they cannot reap its potential benefits. Furthermore, what if an insurance company takes into account a false positive when calculating your insurance rate?
Without appropriate genetic counselling needed to contextualize the genetic information, patients may live their lives believing that they possess some sort of abnormality. They may end up a victim of the self-fulfilling prophecy, internalizing the presumed condition and behaving according to what they expect the symptoms to be.
While personal genomics provides new and exciting avenues for the diagnosis and prevention of disease, its applicability to current medical affairs is still limited by our lack of understanding of the human genome and by the risks associated with having genomic information accessible to the public.
Jeffrey To is a first-year Life Sciences student.