UBC Reports | Vol. 47 | No. 02 | Jan. 25, 2001

The challenges to using genetics wisely

Genetic factors are only part of the story, says Dr. Patricia Baird

The following is taken from a lecture Prof. Patricia Baird gave earlier this month.

We all know the remarkable progress in genetics we've seen over the last several decades.

Specific genes can be identified, sequenced, manipulated, or put into other organisms. A molecular genetic approach has led to greater understanding of numerous specific disease pathways in individuals. Recombinant DNA is used to produce hormones, or vaccines that are useful in treatment.

There has been a media blitz on how rapidly the Human Genome Project is progressing, including even President Clinton and Prime Minister Tony Blair. It's a rare week that the media don't announce that a gene related to some disease has been identified.

As a consequence, there's a widely shared view that the sequencing of the human genome will tell us just which genes cause diseases -- cancer, arthritis, heart disease or mental illness for example. Then, in light of that information we'll design tailor-made new drugs that people will take to cure or prevent disease from developing. In the longer term, we may even re-engineer the genes in question -- we'll fix the responsible gene.

It is promoted by many that there will be a genetics revolution in health care and health. This scenario for the future is shaping the way in which a great deal of research money is spent both by governments and by industry. But is this scenario in fact likely?

Evidence shows that the circumstances we are exposed to over the course of our lives determine much ill health. It's quite true that some individuals are more likely to have disease because of their genetic endowment, but that is only part of the picture.

Each individual also has their own profile of environmental exposures to social/physical/nutritional experiences. Learning more and understanding more about the role of genes in human functioning should be pursued with the recognition that genes are interacting with this variability, so it's not possible to tell a simple genetic causal story for ill health except in some rather rare, single gene instances.

But the conditions from which most people suffer in their adult years will require us to consider both genetic and environmental components and how these interact if we're going to understand them.

The complexity of interacting factors over time on the way to the chronic common disease end-points of adulthood make it unlikely there will be widely applicable "genetic magic bullet" solutions for common diseases.

Genetically based approaches to diagnosis and treatment will have to be tailored to individual variation, and it is not yet clear whether this will be practical or cost effective. To expect genetic interventions alone to be sufficient to make us all healthier is unrealistic.

A great deal of money and a large industry is involved in supplying technology for genetic testing and identification, and in producing therapeutic agents based on a molecular genetic understanding.

Pharmaceutical/biotech companies investing in genetic research have an obligation to shareholders to market and promote the use of a genetic approach to disease. The more it's used, the more successful they are.

In the process, they are likely to divert attention and funding from exploration of other determinants of health.

Biotech companies in the U.S. raised $8 billion a year annually during the mid-'90s and the amount raised has increased since then.

The major U.S. pharmaceutical companies spend 24 per cent of their income on marketing; their sales people make 30 million visits a year to doctors' offices to market their products.

Several other factors contribute to the increasing focus on genetics. One of these is overly simplistic media portrayals of disease causation.

Genetic accounts of the cause of disease are common in the media.

"Genes cause disease" is a simple message which is easier to capture in today's short media formats. Partly as a consequence, many people expect that common diseases will be addressed effectively by genetic approaches.

Scientists like myself in biomedical disciplines also play a role in the focus on genetics.

The human genome project is the largest "Big Science" project ever outside physics/engineering, with many billions U.S. in expenditures involved.

Molecular geneticists in academia have increasing ties with biotech companies. This means that the opinions of academic researchers with investments in those firms or with appointments on boards or as consultants can't necessarily be accepted as objective.

In a rush to a new knowledge-based economy, governments too have often facilitated technology transfer from academia to industry without necessarily taking into account the long-term broad implications, or the need for balance.

They haven't supported to the same degree exploration of other non-genetic avenues to decrease disease incidence -- one kind of worthwhile research has crowded out another.

Lastly, but importantly, genetic explanations are attractive to people in some sectors of society who don't want to deal with complex social and economic determinants of health.

Framing ill health as genetic, and promoting individual genetic or pharmacologic solutions pushes the problem back to the individual. It allows awkward questions on employment policy, or child-care policies, or inappropriate workplace organization, to be avoided.

Clearly there will be numerous specific instances where unravelling some disease pathways or differences in drug metabolism will enable better therapy.

I am not advocating that we stop pursuing these, or that we stop providing genetic services. The individual clinical view of health determinants is important. It underlies medical training and biomedical science, and it provides a framework for the treatment of diseases in individuals.

What I am advocating, is that it's in the public interest to make sure our framework is extended, that other important influences on health are recognized and explored.

A balance in the funding available to do research on what leads to most ill health is needed, because other kinds of questions need to be asked as well as genetic ones. And before large-scale genetic testing or so-called "preventive" treatment is offered to healthy people, there should be requirements to have data demonstrating benefit, that harms are unlikely to occur, and that safeguards against these are in place.

Policy makers should view new and expanded expenditures on detecting so-called risk genotypes related to common complexly determined disorders with a healthy scepticism, and an evaluation of who is advocating such expenditures and whether they are ones who will gain.

We are at a very exciting time in genetics. I think there'll be steady progress in understanding, and in some specific instances in treating particular diseases using genetics. But it's essential to remember that genetic factors are only part of the story.

Dr. Patricia A. Baird is a University Killam Distinguished Professor and professor of Medical Genetics. She has served on many national committees and chaired the 1993 Royal Commission on New Reproductive Technologies. Her current interests include the analysis of social, ethical and health consequences of applying knowledge on human reproductive biology and genetics, and resulting implications for public policy.