March 24, 2011

Alison eagerly opened the results of her genetic test. It was a reversal of the way she felt when the envelope arrived two weeks ago. "You might find out something you wish you didn't know and once you find out, you can't unknow it," she told CBC's science program Quirks and Quarks.

One month earlier she received the kits she ordered, one from 23andMe the other from DeCode Genetics. She spit into one vial and placed a cheek swab in another and two weeks later the envelopes arrived, but sat unopened until now.

She was now ready to face the results. "When I finally decided to open the package, I felt quite exhilarated, like I was opening a box filled with family trinkets that I knew existed but I had never examined before."

Alison Motluk, a science journalist, had agreed to undergo genetic testing and report her findings. Only one decade ago, when the first genome tests were available, the cost would have been prohibitive. But now anyone can get tests done for less than a thousand dollars in the comfort of their home. Just order the home kit on-line and soon, ready or not, your life will be an open book.

Potential buyers are warned to think carefully before jumping in. It's not just you but your entire family who will have their lives laid bare. Fifty per cent of our DNA comes from each parent; you share characteristics with your brothers and sisters. Even if you are willing to peer into the looking glass, relatives might rather stay in the dark about potential illnesses. What if you have a gene for early-onset dementia, would you burden your family with that knowledge? Especially knowing that dementia is untreatable? Perhaps some rocks are best not turned over.

Companies provide some counseling but customers are advised to seek independent advice. After all, these companies are trying to sell kits, not dissuade you from buying them. Knowledge of a life-altering condition is not to be acquired lightly.

And ownership should be considered. Just who owns your genetic information? What if your genes were the key to some miracle treatment, would you control that application and receive compensation?

 

Some of what Alison learned was mundane, some wrong, and some a bit scary. She found out what she already knew; that she was a runner and her face doesn't flush after drinking alcohol, that she doesn't taste bitterness in foods like Brussel sprouts, and that she was lactose tolerant. However, the tests incorrectly revealed that she sneezes when looking at the sun (she doesn't), her hair is slightly curly (it's straight), her eyes are brown and if not brown then blue (they are green). To be fair, the likelihood of each of these characteristics was only a probability and not an absolute fact. She also learned that her disease risks were average for a female of European origin but that she had three times higher risk for exfoliating glaucoma. That was a concern.

How was she supposed to assess this risk? Interpretation of statistics is a problem says Dr. Timothy Caulfield, lawyer and bioethicist at the University of Alberta in Edmonton. The average person doesn't know how to interpret test results when they involve the possibility for developing a particular disease or injury. "Whether it's driving with your seat belt off or dealing with obesity, it's hard to convey a sense of risk." Alison's risk was small; three times a small number is still a small number but the emotional impact could be great.

Dr. Caulfield fears that people will over-react to an increased genetic risk either by seeking unproven therapies or becoming fatalistic. Good news can be equally disastrous. If purchasers discover they have low risk to some disease it could encourage reckless behaviour, like smoking, that would develop disease in spite of low risk.

Promoters of genetic tests say results could lead to preventative steps but Dr. Caulfield wonders how likely that is. Especially when we don't heed the warnings we already have. We are told ad nauseam that we should eat our vegetables, exercise and lose weight but who actually does any of that?

While gene tests hold promise, they currently are not much more useful than simple devices like a tape measure for waist size, a bathroom scale, and a blood pressure cuff.



David Charbonneau is the owner of Trio Technical.
He can be reached at dcharbonneau13@shaw.ca