What your DNA can reveal about your ancestry, health and quirks
Direct-to-consumer (DTC) DNA kits are exploding in popularity as more and more companies offer a service that used to be prohibitively expensive. According to the MIT Technology Review, more than 26 million people have taken a genetic ancestry test. The Technology Review also found that in 2018, the number of tests purchased surpassed sales of all previous years combined. Now, in exchange for a little bit of your saliva, you can have your DNA analyzed and find out more about your ancestry, health predispositions and even personal quirks.
Our bodies are made up of cells. Cells contain DNA, or deoxyribonucleic acid, which provides the instruction manual for our bodies. DNA consists of two strands (the double helix) of chromosomes. Chromosomes contain many genes. Each gene is anchored by a base: cytosine (C), thymine (T), adenine (A) or guanine (G). There are about three billion base pairs of DNA, 99.9 percent that are identical in humans. The remaining 0.1% will have a C, T, A or G variation and this variation explains why we have differences in height, eye colour, hair colour, etc.
When your DNA is analyzed, it’s these variations that are checked against reference populations of other people who probably have brown eyes, or probably have asthma or probably come from South America, etc. Genetics is born from science, but the interpretation of your personal genetic code is more akin to probability within a healthy margin of error. Different companies will draw from different reference populations (and we have no idea how robust these populations are) and use different algorithms, which is why the same genetic material can yield different results from different companies. And as a company gathers more data points from more users throughout the years, it’s possible that your results will change over time as a larger reference population helps make interpretations more accurate.
Considerations before DNA testing
Clearly, variations in genes are common. Many aren’t cause for concern. But sometimes, mutations can result in a gene that gives incomplete instructions to the body or even provide different instructions than expected. It’s possible that your genetic testing could reveal a predisposition to a disease, unearth new relatives (or refute existing relations), etc. Some things to consider before testing your DNA:
- Realistically gauge your emotional bandwidth for receiving potentially significant news.
- If you have a risk variant, it does not guarantee you will actually develop that condition.
- If you receive a “variant not detected” result, it’s still possible you have that genetic variant.
- Sharing your genetic risks might affect your ability to acquire certain kinds of insurance, as they’re grounds for “pre-existing conditions”, which are usually excluded from coverage.
As fun and exciting as DNA tests can be, it’s important that their users understand that results do not constitute medical advice. No one should take healthcare actions based solely on the results of a DNA test. One analysis of raw data from DTC DNA tests cited in Scientific American found that 40 percent of variants associated with specific diseases resulted in false positives. The Canadian Medical Association Journal says, “Genome sequencing [is not] a diagnostic panacea… possible negative consequences are tied to how results are interpreted and disclosed.”
Remember that your genes are not your destiny. It’s absolutely possible that changes to your lifestyle, environment and diet/nutrition may modify genetic interpretation.
Most DNA kits will arrive in a small box that will contain everything you need: instructions, saliva collecting device and return address label/packaging. The box you receive usually serves as the same box you return everything in. Every kit will contain a unique barcode, which you must register online before sending back, so they can track your DNA. Collecting the saliva isn’t as off-putting as it sounds. Just make sure you haven’t had anything to eat or drink or you haven’t brushed your teeth, chewed gum or smoked for at least an hour before collecting the sample. You need to collect about 2ml (½ tsp) of saliva, which can take a few minutes. All collection tubes contain some type of preservative, so follow instructions carefully and return your sample as soon as possible. Results are generally returned in 4-6 weeks.
Before choosing a DTC DNA company, do you research to find one that’s been operating for a while with good reviews. Remember, the more samples it has, the more precise its interpretations are. While you can often find a code or sale online, don’t let price be the determining factor.
Here are two DTC DNA kits available in Canada that have good track records...
23 and Me*
Cost: $129 for ancestry and traits; $249 for health and ancestry.
What they claim: The most comprehensive ancestry breakdown on the market, that includes 2000+ geographic regions, automatic family tree builder, 30+ trait reports and DNA relative finder. For an additional fee, the most complete picture of your health with insights from your genetic data with 65+ health reports and features including health predisposition reports, wellness reports, carrier status reports and family health history tree.
The DNA Company*
What they claim: Our next generation DNA 360 test and report will help you discover exactly what diet, lifestyle, and environment choices can help you avoid health problems. The DNA 360 Report will provide you with reports on sleep, diet, hormones, fitness, cardiovascular system, mood, immunity, detox and more. Each report gives you easy to understand recommendations that help you improve your health.
*Pricing and product descriptions accurate at time of publication.