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When Are Genetic Health Tests Worth Taking?

November 28. 2019. 7 mins read

Investors in Illumina must be stoked about how things have been going so far for a company that commands a dominant market share in one of the most transformative technologies of our time – genetic sequencing. It’s allowed us to pursue promising technologies like gene editing – and now base editing – which means we can start changing the recipe of life, something that falls under the broad umbrella of synthetic biology. Alternative dairy products, lab-grown meat, and disease tolerant crops, are just a few of the products we’re creating on our way to a world where every biological entity is optimized, perhaps even humans.

Illumina’s latest quarterly earnings report had investors growing sour as the company cited a decrease in demand for consumer genetic testing. All those ads on television about finding out who you’re related to have worked their magic. Now, even more Americans can regale you with tales of their Irish ancestry, as companies like 23andMe and Ancestry.com have amassed over 10 million and 15 million DNA samples respectively. If growth is slowing for Illumina, growth must be slowing for the vendors of these consumer genetic tests. That’s why it was no surprise to see Ancestry.com announce the availability of new health tests that aren’t really diagnostic, but are apparently worth $149.

AncestryHealth Genetic Health Tests

Before we dig into the tests, we’ll kill two birds with one stone by spelling out their disclaimer and providing our own commentary in blue text.

  • AncestryHealth® includes laboratory tests developed and performed by an independent CLIA-certified laboratory partner, and with oversight from an independent clinician network of board-certified physicians and genetic counselors. This addresses the whole concern about genetic test accuracy, such as one person taking the test twice and getting two different results.
  • The test results are not diagnostic and do not determine your overall chance of developing a disease or health condition. Key words here are “overall chance.” At the end of the day, it’s either a zero or a one regardless of whatever percentage they give you on the test.
  • The tests are not cleared or approved by the U.S. Food and Drug Administration. Competing tests that are approved will be sure to use this to their advantage.
  • You should consult a healthcare provider before taking any action based on AncestryHealth® reports, including before making any treatment, dietary, or lifestyle changes. Just think about your healthcare provider’s reaction when you say “I took this genetic test for health – no, it’s not FDA approved – and it said I had a 68% chance of getting X disease so what should I do?”
  • AncestryHealth® is not currently available in New York, New Jersey or Rhode Island. How could they omit New Yawk, the greatest city in the world?

Why should you take a test which clearly says that it cannot determine your overall chance of developing a disease or health condition? The answer is because it’s not just about the test, it’s about learning what to do if you’re genetically predisposed to a particular disease. And the same goes for your family members as well. When you purchase the test, you also get access to a “family health history tool” so you can annoy all your living relatives with questions about how your deceased relatives died. Becoming more informed about your family’s health history can’t be a bad thing, and knowing that you’re genetically predisposed to a particular disease could lead to a healthier lifestyle or even extend your lifespan through certain preventative measures.

Taking Preventative Measures

Let’s say you’re a forty-year-old female whose mother was just diagnosed with stage three breast cancer, a disease that several other family members in your family tree have also died from. In this case you may be less concerned with finding out if you’re genetically disposed to any particular disease but rather you want to know what preventative measures you might take to avoid the same fate. You could always just go see your doctor and ask, or you could go armed with a genetic test that says you’re 68% more likely to contract breast cancer in your lifetime. Either way, it’s all about the preventative measures. While AncestryHealth provides genetic health counselors, as the disclaimer says, you should consult with your healthcare provider before heeding their advice, so perhaps what you’re really buying here is a second opinion.

Let’s talk a bit more about the AncestryHealth genetic health tests.

AncestryHealth Genetic Heath Tests

Ancestry has partnered with PWNHealth, an independent clinician network comprised of board-certified physicians and genetic counselors, to offer genetic health tests: AncestryHealth Core (uses microarray technology) and AncestryHealth Plus (uses Next Generation Sequencing (NGS) technology). The latter test is expected to provide more granularity and availability is pegged for early 2020.

Two types of genetic health tests from AncestryHealth
Credit: AncestryHealth

Says Ancestry, “Because the NGS technology is a more comprehensive technology, there may be instances where the NGS results are different than the results previously generated off the microarray. These cases are unlikely but possible given the comprehensiveness of NGS.” (So, if taking the more comprehensive test is unlikely to produce different results, why take it?)

For both tests, there are a number of conditions being tested for which can be seen below.

Diseases covered by the genentic health test from Ancestry Health
Credit: AncestryHealth

Most people probably wouldn’t know much about each of the above conditions so let’s pick one and dig into into it a bit further. We’ll use Hypertrophic CardioMyopathy (HCM) as an example since it’s the most commonly inherited heart disease. (Prevalence estimates range from 1 in 200 to 1 in 500 according to the Journal of the American College of Cardiology.) If you’re thinking about taking the AncestryHealth test because you’re predisposed to this condition, perhaps you ought to know a bit more about what the medical community has to say about such tests. For that, let’s turn to a paper titled “Genetic Evaluation of Cardiomyopathy—A Heart Failure Society of America Practice Guideline.”

Hypertrophic Cardiomyopathy (HCM)

The first paragraph of this paper clearly spells out the purpose:

This guideline describes the approach and expertise needed for the genetic evaluation of cardiomyopathy. First published in 2009 by the Heart Failure Society of America (HFSA), the guideline has now been updated in collaboration with the American College of Medical Genetics and Genomics (ACMG).

This is what the experts have to say about genetic testing for cardiomyopathy, so it’s probably worth a read through if you want to get tested for this particular condition. Here’s what they have to say about whether or not you should take the test:

Therefore, the rationale to identify genetic risk is compelling, so that those found to be at risk can undergo interval screening to detect the earliest manifestations of the cardiomyopathy phenotype. The first evidence of a phenotype then permits earlier interventions, including lifestyle modifications, drugs to slow or halt disease progression or to prevent thromboembolism, and procedures, drugs, or devices to reduce the risk of sudden cardiac death.

So, the experts believe that you ought to take this test if you believe you’re genetically predisposed to HCM. According to the paper, having three generations worth of data is optimal. (Now we can see where the AncestryHealth family health tree comes into play.) Continue reading through the paper and it quickly becomes apparent that the whole thing is far more complex than just a single risk number. For example, check out the below table:

Genetic Evaluation of Cardiomyopathy—A Heart Failure Society of America Practice Guideline
Credit: Genetic Evaluation of Cardiomyopathy—A Heart Failure Society of America Practice Guideline

We’re not qualified in any way, shape, or form to be doling out medical advice, but what the above table seems to imply is that the younger you are, the more frequently you ought to get screened. It also implies that simply having a first-degree relative who has HCM means that you need to get screened at the above intervals regardless of whether or not genetic testing has been performed. It all becomes very complex very quickly, and we’re only talking about one of the conditions AncestryHealth is testing for.

The HCM paper talks about how it’s very early days for genetic health tests. That’s part of the reason that this particular genetic health test suite isn’t approved by the FDA – even they don’t know how to proceed yet. What we find more interesting is what this points to in the future. Someday, every baby that’s born will have a genetic profile that points to a personalized “lifelong health plan” that’s based on all the big data that the medical community has been feeding machine learning algorithms that can make sense of it all. Every single risk will be quantified, every anomaly spotted, every genetic difference accounted for. If you choose not to go down this path with your offspring, they can look forward to higher health insurance premiums and shorter life expectancies.

Conclusion

As we’ve seen with the paper on genetic testing for HCM, trying to distill everything down to a single test is an extreme oversimplification of the underlying complexities each disease has. That’s why AncestryHealth places a great deal of emphasis on their team of professionals who can help interpret the test results to provide actionable recommendations that you can then take to your healthcare provider who will probably refer you to an expert in that field. Any expert should be up to speed on the latest recommendations from the medical community, and that should confirm what AncestryHealth experts told you in the first place. As we said earlier, part of what you’re buying here is a second opinion. If you have two opinions that match, taking the recommended steps should be a no-brainer.

It seems like genetic health tests like the ones on offer from AncestryHealth are worth taking for those who believe they may have a family history of hereditary disease. The whole thing points to a rather clever business model that encourages you to get other family members tested so you can populate your “family health history” tool and better diagnose hereditary diseases throughout your family tree. Just remember that it’s still early days. Recommendations as to how you should proceed if you’re genetically predisposed to a disease like HCM are hardly cut and dry, and it may be quite the can of worms you’re opening for your family. You’ve been warned.

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