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Jim Mumper, M.D.

By: Jim Mumper, M.D. on September 6th, 2018

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DNA Testing: Curiosity vs. Medical Necessity

Genetic Testing

Being curious about who we are, where we came from, and what makes us us is normal. These musings separate us from other animals (after all, Fluffy and Fido don't seem concerned about their heritage).

And knowledge is power, isn't it? The short answer: it depends. 

Consider this example. The movie Apollo 13 is based on the true story about the harrowing days following an explosion aboard the infamous spaceship and how NASA engineers worked feverishly around the clock to bring the astronauts home.

At one point, just as Apollo 13 was getting ready to re-enter the earth's atmosphere, engineers told NASA Flight Director Gene Kranz about a typhoon warning that the National Weather Service had issued on the edge of the prime recovery area. Should they alert the astronauts?

Kranz's response was simple: No.


Because there was nothing that the astronauts could do with the information. In other words, the knowledge didn't provide power—it was just knowledge.

Now, let's apply this analogy to genetic testing. We can now map a human being's entire genome, which is a huge accomplishment. But just because we can, that doesn't mean we need to do so for every person on the planet, at least not yet.

Why? Because the science is still catching up. Yes, we have the ability to map a person's genes (all 20,000+ of them). But reading that map, that blueprint, and understanding what each gene means for that particular human? That's the part science is still figuring out.

In fact, the National Human Genome Research Institute says as much when it notes that the success of the Human Genome Project (HGP) simply marked the "end of the beginning." The website cites physician-geneticist Francis Collins in a 2001 article for Genome Research:

"Critical understanding of gene expression, the connection between sequence variations and phenotype, large-scale protein-protein interactions, and a host of other global analyses of human biology can now get seriously underway. For me, as a physician, the true payoff from the HGP will be the ability to better diagnose, treat and prevent disease, and most of those benefits to humanity still lie ahead."

These words still resonate, even 17 years out (because 17 years is a drop in the bucket in terms of time).

That's not to say genetic testing (also known as DNA screening) is useless or that we haven't seen excellent advancements in the last two decades. For certain specific purposes, DNA testing can be extremely insightful and useful. Testing the genes found in cancer cells can guide treatment protocols, for example. (Here's an article from NPR that talks about a breast cancer genomic test that does exactly that.)

Or if you're curious about your ancestry, as many people are, doing a DNA test so you can trace your heritage is both fun and informative. Again, this is a very specific purpose. (And keep in mind those ancestry tests are less thorough and less accurate than DNA screenings your doctor orders.)

But you should remain skeptical of any health care company or practitioner offering a "complete" screening that promises endless insights and actions that you can take based on those results. Because, again, scientists have just started to scratch the surface when it comes to understanding the story any one genome is telling.

You should also remain wary of screenings that don't include any sort of pre-counseling and discussion. Both are critical in determining the test's medical necessity and the ways the results might affect you. To that point, the American Medical Association's Code of Medical Ethics states, "Physicians should not encourage [genetic] testing unless there is effective therapy available to prevent or ameliorate the condition tested for."

And if a test is medically necessary, a genetic counselor will help you understand the results—and your emotions around those results.

At PartnerMD, we practice personal medicine that's designed around your unique needs. We will never present genetic screening as a panacea for all patients. For some patients, genetic testing might make sense. For others, maybe not. And over time, as researchers make new discoveries and advancements, we'll adjust our recommendations accordingly (another benefit to the way we practice medicine is our physicians have the space and time to keep up with the research).

Interested in learning more? We encourage you to download our free guide on genetic testing, which takes a deeper dive into what it is as well as the pros and cons.

About Jim Mumper, M.D.