Understanding the human genome will have a transformative effect on health and on our health-care system. This revolution will fundamentally alter the way we prevent, diagnose, and treat diseases even as it poses ethical problems about privacy and confidentiality that we are only just beginning to grasp.

At the moment, our health-care system is primarily reactive -- we treat people when they become ill. With the new knowledge that we are gaining of the human genome, we will be able to predict who is susceptible to disease and help to prevent the disease or catch it at an earlier, treatable stage.

For example: We can now identify people who carry an altered gene that predisposes them to colon cancer. Armed with this knowledge, we can look for and remove the pre-malignant growths before they become cancerous, preventing deaths from this disease.

Diagnosis of disease will also change radically. Instead of symptom-based diagnosis -- we know the car won't start, but we don't know why -- we will be able to make a diagnosis based on the molecular pathways that are altered. We will know whether the car won't start because the battery is dead, or the gas tank is empty. Just as battery or gas-tank problems require different solutions, the genetic variations of a disease require different approaches. Patients will be stratified according to the genetic pathway their disease has taken, and treated appropriately.

We can already see the potential benefits of such individualized medicine. STI-571 is a drug being tested as a treatment for chronic myelogenous leukemia. It is designed to interact with the ABL protein, the protein coded for by the ABL gene that is responsible for the abnormal growth of leukemic cells. Early results are highly promising; the drug is very effective and has few side effects. In short, we are rapidly moving from reactive to proactive approaches to health and to diagnoses based on what our genes are doing, not our symptoms.

The genomic revolution, and its implications for health research, is also fuelling the growth of Canada's New Economy. For Canada, the economic potential is enormous. We have one of the world's most vibrant biotechnology sectors -- companies that are leaders in developing new therapies for HIV/AIDS, cancer, infectious diseases, blindness, heart disease, etc. These companies have grown out of the innovative research carried out at our universities and research hospitals. They now employ hundreds of young Canadians, and are supported by more than $500-million annually.

But . . .

We are still far from having all the answers. If the human genome map is the Book of Life, then we still don't completely understand the language in which it is written. Deciphering that language -- figuring out what our genes actually do -- is going to be an exciting challenge involving more than just geneticists.

Proteomics will be an important piece of the puzzle, since genes are simply blueprints for proteins. Bioinformatics will be another part of the puzzle. Integrative physiologists and clinicians will bring their understanding of the whole person to the table, while organ specialists will help us understand how genes affect the development and functioning of our heart, lungs, liver, brain and other organs. Social scientists are essential if we are to understand the complex interplay between genetics and external factors, such as socio-economic status, lifestyle, and the environment. Some diseases such as Tay-Sachs and cystic fibrosis arise only as a result of mutations in a single gene. Others, such as diabetes and various mental illnesses, appear to reflect the complex interplay between our genetic hard-wiring and what we eat, who we know, how we live.

And more than ever, we're going to need ethicists. The genetics revolution is raising countless new ethical issues. The ability to predict disease, decades in advance, has profound implications for how we view our lives and make life decisions. How will new genetic information affect our decisions about whether to have children? What should we tell them? What should they tell us?

Issues of privacy and confidentiality are critical, as is the need to deal with the issue of discrimination in the workplace or by insurers. Will employers have the right to genetic information about potential workers? Who has the right to this information? Our bosses? Our future spouses? Our insurance agents?

The development of new therapies raises issues of health disparities. New drugs are expensive, and the pace of development is rapid. Access to these drugs is going to vary, not only between the developed and developing worlds, but within regions of Canada and between Canada and the United States.

Our governments need scientific, objective evidence in order to make informed policy decisions about the avalanche of new treatments. Will this ultimately mean that the health-care system becomes more cost effective? Or will costs rise as the public's expectations continue to increase?

In last month's Speech from the Throne, Ottawa recognized the driving force that health research will play in ensuring the health of Canadians and of the health-care system. It implicitly recognized that today's challenges -- a vibrant and efficient health-care system, the health of our aboriginal population, healthy children, a strong and diversified economy and the branding of Canada as a country characterized by excellence, creativity, free enquiry and opportunity -- requires a strong culture of research. I have no doubt that Canada can lead the world in this new science and develop a uniquely Canadian approach that balances the exciting scientific opportunities with the ethical and social challenges for the benefit of all.

Dr. Alan Bernstein, an internationally known researcher in cancer and gene therapy, is president of the newly created Canadian Institutes of Health Research.