Guest Post: Putting GC into DTC

Jill Davies is a Genetic Counsellor and the Director of Genetics at the Medcan Clinic, Canada’s leading preventive health care clinic. She has over 10 years of experience in genetic counseling and has worked in partnership with Dr. Lea Velsher (medical geneticist) to develop a preventive genetic service at Medcan.  Read her full bio here.

We’ve spent a lot of time discussing why DTC genetic testing shouldn’t be available, but I think we’re beginning to come to terms with the fact that consumer genetic testing is here to stay.  Rather than criticize, why don’t we look at embracing the technology and building a framework around how it can work?

For the past 4 years, I have worked at a private medical clinic in Canada .  More specifically, I have worked at a preventive healthcare clinic, where we focus not on health care as an expense, but as an investment.   Believe it or not, there is a large market for preventive health care. This growing area of medicine aims to focus on detecting disease early, when there is opportunity for treatment and improved outcomes.  A large part of this concept is health education, of which genetics education – understanding how genetic factors play a role in overall risk for disease – is often overlooked.

Family history is of course an important component of understanding one’s potential genetic risk and this is still the best place to begin any genetic assessment.  When I started at Medcan more than four years ago, my job was to meet with people as part of their annual medical and help them to understand their genetic risk based on family history.  The vast majority of conditions that people were concerned about were complex diseases, like cancer, heart disease and Alzheimer’s.  Conditions where I might rarely see an indication of inherited risk, but most often spent my time counseling around risk factors for common diseases.  Although I knew the information we were providing was important, only a portion of clients found value in this genetics education piece.  Many others found the information to be lacking – they wanted something more tangible.  They wanted genetic testing.

About a year ago, we started having discussions with Navigenics, a company who employs genetic counselors and who’s SNP panel is carefully vetted by a large team of scientists and geneticists.  Yes, I spent some time researching the other DTC companies, but it quickly became clear to me as a genetic counselor that only one company had figured out the right formula – as their slogan says “There’s DNA, and then there’s what you do with it”.  For those of you who haven’t had the opportunity to see a full Navigenics patient report, I encourage you to try to get your hands on one – its good!

We took a look at this report and thought “how can we build on this?”  As we’ve already established, there is clearly a market for preventive health and my experience was definitely telling me that people wanted more than just a family history review.  So why not combine family history, with personal genome testing technology?  Better yet, why not offer pre- and post-test genetic counseling sessions too?  This way, individuals have the opportunity to learn about the test in advance (risks, benefits, limitations, insurance issues) and also have a qualified professional to walk through the results and help interpret those results in the context of the family and medical history.

The biggest complaint about DTC testing to date has been the lack of qualified professionals to help individuals understand what the information means.  Although there are still limitations to our understanding of the clinical application, I don’t think we give consumers enough credit in their understanding of probability and risk stratification.  And I don’t think we give ourselves enough credit in our ability to counsel around these complex issues.  We’ve been doing it for years.  This is just a new framework in which to use our skills.

The uptake of our service has been very successful with our clients.  I’ll be the first to point out that we have a fairly unique patient population – high income earners who are already interested in proactively managing their health.  Anecdotal trends so far though indicate a low level of anxiety and a high degree of satisfaction with our program.  A program which allows the technology provided in a DTC test to be made available in the framework of genetics best practice.”


Filed under Guest Blogger

9 responses to “Guest Post: Putting GC into DTC

  1. Heather

    Hi Jill,

    Thanks for this interesting post. I am wondering if you could clarify a couple things for me since I don’t know much about this topic:

    1. For an individual who knows most major diseases in their family (siblings, parents, grandparents, and uncles and aunts), is there evidence to suggest that doing this type of genetic testing gives risk information you can’t tell from taking a thorough family history on its own?

    2. Is there evidence, published or anecdotal, that shows that people actually use their genetic testing information to make lifestyle changes to prevent the diseases they are deemed ‘at increased risk’ of? For example, everyone (no matter if they’ve had this genetic test or not) knows they should exercise regularly, avoid junk food, refrain from smoking, reduce their stress, etc. I am looking for evidence that having a genetic testing result like the one from Navigenics actually results in positive lifestyle change.

    Thanks for the time you took in writing this for all of us!


  2. MS

    Interesting post! I think the field of genetic counseling will only grow with this type of DTC testing. After all, if a patient does testing through a company like Navigenics and brings their report to their primary doctor for questions, who do you think that primary doctor will refer their patient to? GCs or med geneticists I hope. Of course GCs and the genetics community really needs training and to get “up to speed” on how to interpret these reports ourselves.

  3. Jill Davies

    Hi Heather,

    Thanks for your questions:

    1. There are some pretty significant limitations when using family history to assess risk for complex diseases. As we all know, most of these diseases are multifactorial and we rely on empiric risks from population based studies. Which really means that we are giving relative risks based on family history in the same way that we give relative risks based on known environmental factors, or in this case on genetic variants (SNP’s). Some of the genetic markers on Navigenics’ panel carry more significant odds ratios than family history alone. Examples of this would be SNP’s for AMD (some markers have odds ratios of 10+), Celiac disease (one marker has an odd ratios of 49) and Alzheimer’s disease (odds ratio of 21). As a comparison, family history typically carries an odds ratio of 2 for most diseases.

    Family history alone often fails to show all of the risks that an individual may carry. For example, 89% of individuals with prostate cancer and 76% of individuals with breast cancer have no known family history. There are situations where family history is unknown (either partially or completely – ie. adopted individuals) or where family size is too small to assess the contribution of genetic risk in common diseases. What I didn’t mention in my blog above was that the Personal Genome Testing (PGT) at Medcan is an opt-into service that we provide only after an individual has had a family history review. There are some clients who choose not to have PGT. However for those that do, we have chosen to look at family history alongside DNA results so that we can give the best possible interpretation, knowing that there are still limitations to that interpretation – in the same way that there were limitations when we used family history alone.

    2. There have been a number of reported studies that suggest individuals use this information to make positive behavior changes:

    Chao S, et al. Alzheimer Dis Assoc Disord 2008;22:94–97

    Sanderson et al. Cancer Epidemiology Biomarkers Prev.2009; 0: 1055-9965.EPI-08-0620v1

    Sanderson SC, et al., Public Health Genomics , 2009, DOI: 10.1159/000217794

    As you may be aware, Scripps is working on a 20 year study looking at genomic testing and behavior change and they have recently presented the first round of data. We (Medcan) also recently sent out a client survey following the first 6 months of program implementation with very positive client feedback – 100% of individuals felt that they received something of lasting importance or value from our program, 69% said they had undertaken dietary changes that may influence future health outcomes, 77% said that they had changed their physical activity in such a way that may influence future health outcomes and 31% said that they had undertaken additional screening or testing options. Again, our population may be unique, but I think different individuals will use this information in different ways. I think its also important to bear in mind that some people will benefit from recommendations that are in addition to generic lifestyle recommendations. For example enhanced screening (mammography, colonoscopy, optometry exams), avoidance of gluten, lactose, iron-rich foods etc.

    Thank you for your questions. I think there is still a lot to be research and learning to be had in this area. We are looking forward to undertaking some comprehensive research studies in the future and hope to publish some of our findings.

  4. Hi Jill,

    It is great to hear that such a comprehensive service exists already. It was very forward thinking of Medcan to bring a genetic counselor into their service 10 years ago.

    I wanted to reply to Heather’s question about whether there is evidence regarding the utility of personalized genomic information. At this point there are very few studies that have looked at this, may of which are focused on a single disease (genetic variant related to nicotine addiction, lifestyle changes in response to APOE results for Alzheimers) rather than testing across multiple conditions. Coriell is doing a research study to look at the utility of personalized medicine which involves reporting results for multiple common complex disease risk (coronary artery disease, type 2 diabetes, etc) based on genetic risk information as well as family history risk information and non-genetic risk factors (smoking, BMI) and then surveying participants regarding what they did with the information and if they shared it with their physician, what their physician did or recommended in response. Data from our first outcome survey on coronary artery disease will be presented next week at ACMG. Information about our study and sample results can be found on our website


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  7. Madhavi Raj

    Even if we know the family history for a particular disease we should still go ahead with DTC?

  8. Pingback: As a Genetic Counsellor, Would You Go Public With Your Genome? | The DNA Exchange

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