We’ve already gone over the basics and science of genetic testing at-home in DNA Testing 101. We explored the positives and potential downsides of undertaking this kind of testing in Pros and Cons. We even prepared for what you may find through a DNA testing kit, in our article on Inherited Disease and how illness runs in the family.
For many people, the topics we’ve covered are relatively easy to grasp. Ultimately, you don’t need to know how genetic testing works to make good use of the results. However, these results may not be simple - a whole science exists to interpret these kinds of tests: genetic counseling. Right out of the gate, I’ll say that if you’re willing to shell out for a session with a genetic counselor, it’s well worth it. They can analyze your medical and family history, lifestyle factors, as well as your genetic data. These professionals are specialized in this type of interpretation; they’re often more well-read on the recent advances than your average GP.
However, many people opt for at-home DNA testing because they do not have access to this level of personalized attention. When the results of a DNA test indicate that you may have negative risk factors or predispositions - or even if the data is inconclusive - there are some immediate steps you can take to calm your mind.
This section largely only applies to the service provided by 23andMe. This FDA-approved kit provides a level of detail on health-related issues that other at-home tests can’t match. While the competitors mainly focus on ancestry, and the health-associated correlations that exist for certain populations, this isn’t a proxy for assessing the disease-related genes themselves. This health-focused approach by 23andMe is a double-edged sword. It provides a massive amount of data, but the applicability isn’t always so clear.
Wellness-related suggestions are often quite actionable, but may not be completely accurate - they’re the kind of results with the least understood mechanisms. Data is usually drawn from correlational studies of specific populations; a wider application is not always guaranteed. Predispositions for certain serious illnesses tend to scare consumers the most when they first receive their DNA testing results.
These estimates are primarily based on known, understood mutations in certain genes that result in a significant increase in the risk of disease. Some predispositions, like for Type 2 Diabetes, can be avoided with specific lifestyle changes. Others, like for Alzheimer’s Disease, may leave you feeling helpless.
If you received some concerning DNA test results, the first weapon to combat fear is knowledge. Understanding how your results are generated can give you a better idea of how you can influence your risk. It may also uncover information that reveals a lower risk than initially assumed; some predispositions are only valid in certain populations or given specific lifestyle factors. Resources to find this kind of information are often supplied by the service that analyzed your DNA.
Further, a thriving online community of genetic explorers have all but removed the shroud of mystery surrounding the interpretation of a DNA test. If you’re driven and technically-minded, you can also opt to download your raw DNA data for an even more in-depth analysis down to each genetic variation.
For consumers who don’t have that kind of time to spare, there is a growing number of 3rd-party services that can analyze, explain, and summarize the raw data provided by an at-home DNA kit. However, this is yet another expense, and it still doesn’t give the peace of mind that would come from a medical professional. These kinds of services are for people who want the most actionable lifestyle guidance, less so for individuals seeking medical reassurance.
DNA testing kits only look at one thing: your genes. Unfortunately, while they’re the building blocks that make you you, they aren’t the most reliable predictors of most ailments.
BRCA mutations are a great example, the best-known variants that increase your risk of reproductive cancers. Ultimately, only 5-10% of reproductive tumors carry a BRCA mutation, indicating that many other factors contribute to the development of cancer. On top of this, 23andMe only assesses three of the most important BRCA variants, out of the thousands that have known risk associations with illness. Let’s put this in context: Two women completed an at-home DNA test kit from 23andMe; both women discovered that they have risk variants in BRCA genes.
While both women have a genetic predisposition to BRCA-associated cancer, they have very different overall risk. In this example, I’ve listed some of the most well-known indicators of a predisposition for breast cancer. This is a very extreme example, but it illustrates that genetic testing does not stand alone in determining risk.
In the end, at-home DNA testing is not meant to be diagnostic. Frankly, there isn’t any result that would require immediate action. These tests are meant to inform and educate, perhaps also to direct focus to the most impactful lifestyle adjustments. While many predispositions may not seem actionable on the surface, they’re an excellent opportunity to reflect on your current situation and lifestyle choices.