Personal Genomics: Is knowing MORE better than LESS?

Like the total-body MRI, it raises my eyebrows.

Are you SURE you want that?

Are you SURE you want to know every detail of what might be wrong with you, even if it might not actually be something causing trouble, and might be something that you cannot change?

For some people, the answer is YES.

For others, NO.

Personalized medicine, the kind of medicine that suggests individuals undergo genetic and molecular tests in order to develop customized care plans, is in the news. The Vancouver Sun has recently hosted an interesting series of articles all about this technology. It could save lives. And it can be an expensive, slippery slope. (See: Genome sequencing: A costly way to save).

Dr Brad Popovich, chief scientific officer of Genome British Columbia, discussed his own experience with genetic testing with the Vancouver Sun (Personal genomics: The test for everything (with video)). It is illuminating to read about the experience of a researcher and his questions moving forward. However, as staff and CSO of the organization, of course he needs to promote his work and his company's mandate; I'm not sure his experience is reflective of the average person's when thinking about genetic testing.

Another perspective is offered in the Sun by Dr. Matthew Farrer, Professor of Medical Genetics at the University of British Columbia (No quick genetic fixes for complex diseases). As he points out, it's nowhere near as direct a process for diagnosis as some might think:

“The average human genome gives you something like four million variants from one person to another. So, to interpret what those mean and what the consequences are to a person’s future well-being or susceptibility to disease is a pretty grey box.”

This article points out there may be an important role in mental health screening and lending clarity to diagnosis. Other articles document the benefits in assessing familial risk & individualizing cancer treatment or testing prenatally for conditions that are preventable or treatable if caught early on.

Unfortunately, there are lots of issues beyond the fact that this technology is in its infancy. Some things may improve as the body of research grows: the cost, the specificity, the availability. However, significant ethical issues may (rightfully) be a barrier to further advancement and application of this kind of testing.

Most diseases result from a combination of genetic and environmental factors. Some are predictable, and others less so. Some genetic predispositions never manifest as disease, or the disease can be more extreme than the tests ever suggest. That's the beauty of life - we cannot know the future. However, sometimes knowing what to expect can be helpful.

For example, in prenatal testing for Down Syndrome risk, some parents prefer to have an idea if their child might be affected so that they can read and prepare. Some parents may want to know about risk for the disease so they might choose to abort the pregnancy.  Other parents decline the testing because they will love and work with the child however they are born. Unfortunately, the testing is not perfect, there are many false positives and some false negatives.

The vagueness of genetic testing is a real challenge and may be confusing to patients as it may lead to greater uncertainty. As mentioned in the Personal genomics: The test for everything (with video) article, it's not only the patient who has to deal with the results:

Popovich’s decision, made with his wife Nicola, was made simpler because the two have no children. The presence of hereditary disease in his genome has no downstream impact . . .

Having your genome sequenced may have implications for your children, and the potential for this will have to be weighed before embarking on any such testing. Less importantly, there may be implications for life insurance and medical insurance eligibility, where universal healthcare is not available.

At The Conversation, Jacqueline Savard's essay, How genetic testing is swelling the ranks of the ‘worried well’ highlights some of the negative issues, particularly those under the umbrella of Overdiagnosis.

... genetic testing has the potential to give [patients] a label, adding them to a growing class of citizens, the “worried well”. These people are not ill as they don’t display symptoms of the condition with which they are labelled. Nor are they clinically diagnosed as having the disease in question. Instead, they are at a pre-phase, they are now genetically at risk for a particular disease. But the date, time, and list of symptoms they’re likely to experience or the severity of the illness are yet to be determined.

There are societal implications as well.

For society, the implications of genetic testing and over-diagnosis is the opportunity cost of treating the genetically at risk rather than those who are symptomatically ill. In the struggle for scarce resources, decisions are made between who and what diseases will receive the funds they desperately need.

Ms. Savard generously searches for a silver lining, but finds it to be false:

One potential (and limited) benefit of these tests is the creation of new markets for drugs or preventative treatments that can flourish as more people are labelled with conditions. But with health-care costs increasing and the need for rationing a central concern, there’s also the danger that resources will be diverted from public health measures that have a chance of preventing genuine illness in favour of treating “pseudodiseases”.

We don't need more disease. And we certainly don't need more diseases invented specifically in order to sell medications. But we do want people to live as well as is possible, at the same time allow the our natural course of existence to unfold.

As with everything, the answer probably lies somewhere in the balance. Perhaps a few very specific genetic tests will offer a cost-effective way to diagnose and even prevent serious ailments that are otherwise difficult to assess. The murky, inefficient, and ineffective tests can be abandoned so that we might focus on the other things that matter. 

If you don't feel sick and you are living healthfully (on your own terms), is that good enough? Isn't it?