Tag Archives: whole genome sequencing

VARIATIONS IN A MINOR KEY: SOME THOUGHTS ON PRENATAL TESTING IN AN ERA OF WHOLE GENOME SEQUENCING

James Watson is many things – geneticist, Nobel laureate, agent provocateur – but in the realm of psychiatry he is first and foremost the parent of a son with schizophrenia.  So when he spoke in 2007 at the World Congress of Psychiatric Genetics, it was as a family member, albeit a family member with an unusually good grasp of the science.  And it was as a family member that he exhorted the scientists in the audience to keep up the good work, so that “someday we could identify those individuals destined to suffer from mental illness in utero, and weed them out.”

How often do you hear an audible gasp in the midst of a plenary talk?  The dismay and the indignation were palpable.  Researchers throughout the day interrupted their talks on GWAS to express in the strongest possible language that the goal of their work was to understand the pathophysiology of the disease and perhaps to aid in diagnosis – not to provide pre-symptomatic risk  assessment and not – no, never – not to be used prenatally.

“But if this is what families want,” I asked one speaker later that day.  “How do you propose to restrict testing, once the means to test is available?”

“They can’t,” he replied.  “They must not.”

Ah.  Of course.  They must not – I will pass that along.

Five years later, it is not GWAS but whole exome sequencing and whole genome sequencing providing all the buzz at conferences.  Solving the diagnostic odyssey!  Revolutionizing cancer treatment!  Ushering in an era of personalized medicine!  It’s very exciting.  Prenatal testing is rarely mentioned, and then only in passing – while prognosticators sing happy songs of a not-so-far-off day when every baby will be sequenced at birth.

Sequenced at birth?  Will it even be necessary?  Maybe Mom and Dad have baby’s DNA already, on a hard drive or a memory stick or downloaded onto their cell phones along with the ultrasound pics.

This is not the genome sequencing story you are seeing in the papers or the blogs.  It’s not what researchers are excited about.  The ones we hear are all about science journalists getting their DNA decoded and setting off on odysseys of self-discovery that involve hours of consultation with clinical and academic superstars who donate their time. We hear about kids with strange constellations of symptoms finding answers after years of disappointment.  Those are heartwarming tales: anecdotal and difficult to imagine at scale, but hopeful and exciting nonetheless.  But there is another theme playing, in a minor key, and I hear it faintly, hidden beneath the violins and the trumpets.

I hear it, an unspoken question, when we debate the utility of genomic information.  What does to mean to say that information is actionable? (Prevention? Treatment? Cure?  Prenatally, there is only Yes or No.)  Can patients handle uncertainty?  (And what will we lose, when pregnancies are terminated just to be on the safe side?)  Doesn’t everyone have the right to know what is in their own DNA? (The information is available – why not use it?  What could possibly go wrong?)

Whatever tests are available postnatally will find their way into prenatal use.  The gateway technologies – PGD, cell-free fetal DNA testing – are in place. And there is no use saying, “they can’t, they won’t, they shouldn’t” because they can and they will – and sometimes they should.  There will be good uses too: success stories and disasters averted.  A blanket “no” is not an option, and granting anyone authority to pick and choose which uses are worthwhile vests altogether too much power in the hands of any one person, or profession, or bureaucratic entity.

The same tests can be done before or after birth, but the experience is entirely different.  Uncertainty after birth is an opportunity.  The least useful information is that which will absolutely come true, no matter what you do.  Uncertainty before birth is a crisis.  Anyone who has ever discussed a variant of uncertain significance with a pregnant mother can tell you that.  But what are the chances there will be developmental delay?  Are you certain that the heart will be affected? How sure are you that this means anything?  Not nearly sure enough.  Please understand that.

In general, notions of genetic determinism increase the likelihood that genomic testing will have negative consequences.  Fatalistic attitudes about the power of genes could lead people to overestimate the meaning of elevated risks and underestimate the meaning of reduced risks.  Anxiety, stress, missed mammograms – you have heard this before.  Shrug.  People are grown ups.  They will figure this out.  Information is power.

But we are in a whole new universe trying to reconcile underpowered and often misunderstood predictive testing in the context of prenatal use.  So please, in telling tales of all the wonderful things that genome sequencing will do, save space for a mention of what it cannot do.  Make sure they understand that there are great wide cracks in our crystal ball.  Do not oversell the value of genotype in the absence of phenotype.  Remember that in the end neither researchers nor physicians nor genetic counselors will dictate how this new technology will be used.  Others will make that call, and we will be in the choir, singing songs of praise laced with sorrow.

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As a Genetic Counselor, Would You Go Public With Your Genome?

A Canadian version of the Personal Genome Project (PGP) was launched earlier this month. This is an initiative that, for one key reason, is likely to have a rippling effect for the genetic counseling profession. Modelled after and in collaboration with George Church and his group at Harvard, the project aims to recruit 100,000 volunteers to have their whole genome sequenced and posted publicly online for the advancement of research. As someone who has followed the US Personal Genome Project from the outset, I’m thrilled that Canadians will now be able to participate in this important research.

So why is the Canadian version of this project so important for genetic counselors specifically? Because the first participant (whom the media has aptly named Canuck One) to bravely volunteer to “bare her genomic soul” and forgo any form of anonymity while doing it, is a genetic counselor. Jill  Davies and her involvement with PGP-Canada was profiled in The Globe & Mail (one of Canada’s largest national newspapers) earlier this month.

Globe and Mail PGP-1

In full disclosure, Jill Davies is a close colleague and friend (and also a previous guest contributor to The DNA Exchange). The Medcan Clinic genetics program has been involved in the PGP-Canada project from the outset, and therefore it is no coincidence that Jill happens to be participant number 1. But it is also precisely the fact that she is a genetic counselor that the PGP team was keen to have Jill step up to the plate. Who knows the potential implications—clinical, ethical, legal and social—of whole genome sequencing better than a GC? Beyond immersing herself into her work (quite literally), Jill’s participation will undoubtedly help raise awareness of the genetic counseling profession, which is something that I think should be celebrated.

Not surprisingly, with the potential to have my own whole genome sequenced hitting closer to home, I’ve been thinking a lot about whether this is something I would go through with, and if not—why?

The Globe & Mail has done an excellent job in asking the general public this very same question. In conjunction with the official start of the PGP-Canada project, the newspaper launched a widespread interactive media series — The DNA Dilemma—running from December 8 to December 22. This is one of the biggest and most comprehensive genomics-related media series I’ve seen. It is really worth the look at the articles and commentary. They have even developed a genomics game: Win, Lose or Genome?

By far the most interesting component to the series for me is the Infographic-type Poll on whether people would choose to have their genomes sequenced. Of the 1000+ respondents so far, a whopping 80% say they would have sequencing, and 70% believe the benefits outweigh the risks (you can filter the results based on age, gender, location etc). As a genetic counselor I find these numbers fascinating (and surprisingly high).

Globe and Mail Poll

My hunch is that if we polled GCs specifically, this number would be lower. There are so many interesting questions about why this might be—is it because we are more informed? Is it because we are a self-selected group who are more attuned (and potentially concerned about) the ethical issues associated with genetics to begin with? If I had the skills to create such a beautifully intricate poll as the one above I would, but I’ll have to make do with the standard DNA Exchange poll to test my theory. So—what do you say? Would you participate in the PGP?

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What Genetic Counselors are Talking About

Last week, I attended the National Society of Genetic Counselors (NSGC) Annual Education Conference in Boston. Although I attended talks on a variety of subjects, where possible I chose sessions focused on new genomics technologies and associated issues. There were some common threads tying these discussions together beyond ‘genomics’ itself. Here’s a quick summary of some of the things I observed and learned.

1. Secondary, Ancillary, Incidental – Oh my!

It is no surprise that discussions around the use of Whole Genome Sequencing (WGS) and Whole Exome Sequencing (WES) universally include the question of what to do with the “extra” data—those pieces of information we weren’t looking for, but happened to find. What was surprising are the differences in the terminology we use to describe these extra pieces of data. Jessica Everett, a GC from the University of Michigan Mi-OncoSeq project explained that confusion over this terminology lead her team to decide that they would universally refer to an incidental finding as an unintended piece of information that “falls into your lap” and a secondary finding is extra information you end up finding out, but have to look for.

There are likely some official definitions and designations that already exist here. But it is apparent that we as a GC community currently don’t have a consensus on the nomenclature around this issue.

2. GCs don’t need new skills, but rather need to apply our skills in new ways.

This type of thinking is music to my ears—I love the challenge of applying our skills in new and unique ways. The GC role in pharmacogenomic testing specifically was a sub-theme here. I heard multiple genetic counselors who work in the realm of pharmacogenomic testing say that while they initially believed their role with patients undergoing testing for pharmacogenomic purposes would be minimal, the applicability of our traditional skills and opportunity to provide value to both patients and physicians was far greater than they anticipated. 

3. “Scalability” of the Genomic counseling session

The sheer volume of information and amount of time required to consent patients for WES/WGS technologies was routinely cited as a barrier to genetic counseling in the genomic era. In some cases, GCs plan for a 2+ hour pre-test counseling session, and in most cases there are multiple visits or contacts before testing is initiated. There was also alot of discussion about how best to inform patients about the various types of information that can be learned through genome sequencing technologies. Bioethicist Scott Kim (also from the Mi-OncoSeq project) made a good case for a ‘flexible default’ model for informed consent in these situations.

Consistently GCs commented that when asked ‘do you want to know everything?’ patients and research participants will almost always reply ‘yes– of course I want to know everything!’ However, the use of specific scenarios or examples seems to be required in order to elicit a more meaningful discussion about potential results, and what information patients will decide to opt out of receiving. (This is a topic I’ve previously written about.)

4. Collaboration

Although this may be the least exciting or surprising underlying theme, it is likely the most important. Almost every lecture concluded with a slide highlighting the importance of a collaborative and multidisciplinary approach to genomic testing.

As always, I’d love to hear about others’ reactions and impressions from this year’s AEC. Please feel free to share, below.

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