Why would I pay 20 times more for some DNA tests?
DNA tests all have the same objective: to give you information about your unique genetic predispositions. Today, you can learn about your ancestry, physical traits, predisposition to drug dependency as well as your predisposition for curable and incurable diseases in a matter of weeks. But how come no single DNA test provides you with all this information at once? And how can tests possibly range from €100 to €2000 for what seems to be a similar process?
Think of it as the media industry. The accuracy of what you will learn depends mainly on the source, the size, the quality and the interpretation of the data you have access to. However, sensational news might sometimes be more appealing than thorough journalistic work. This is why some value The Economist more than LADbible, and vice-versa.
For DNA testing, it all comes down to finding and interpreting variations in your genetic code. To achieve this, not all DNA tests are equal. Today, we tackle the 2 globally used technologies in DNA testing and what you can expect from both of them.
We will talk about the use of data and companies’ revenue models in a later article: subscribe here to not miss on our next articles.
Quick genetics refresher
Before going into the details of the two methods used by DNA test providers around the globe, let us remind you about how your DNA works. The DNA found in your cells is composed of 3 billion letters also called bases. Each letter or base can be either A (adenine), C (cytosine), T, (thymine) or G (guanine). This sequence is essential for your cells to work properly.
What makes everyone different is variations in this long sequence. There are different types of variations possible in your DNA. Either a letter can be switched to another like an A becoming a G, one or more letters can be deleted, or one or more letters can also be inserted. Some of these variations cause changes like different eye colours, but, in worst case scenarios, changes can also cause diseases. Over the years, scientists have been able to associate specific variations to traits. It is now possible to deduce your ancestry, physical traits, and even increased risk to diseases from these variations.
The direct-to-consumer revolution: Genotyping.
In order to make DNA tests known publicly, it had to be affordable. For this, the low costs associated with genotyping were the perfect match.
Genotyping is essentially looking at your DNA and seeing whether there is a particular letter (A, T, C, or G) at a specific location. Much like running a keyword research in a digital book, it would be like checking for a specific word or word typo assuming you are sure about what you are looking for. For example, it would be like going to page 135, line 23, word 4, and checking whether there is the word “grey”. The answer would either be a yes, there is the word “grey”, or a no, there is not the word “grey”.
Although genotyping is fast and cost-effective, its limits are due to current knowledge and the amount of searched variations. As science evolves everyday, a test running on genotyping has chances of becoming obsolete in a matter of months since the DNA variations detected are only those we know about today. The panel of variations (the set of keywords we search for) is determined from the start and dependent on the current state of science. Additionally, the type of answers from these tests are yes or no. If the variations we looked for are not present, there is no way of knowing if another variation is present.
While this technology would not be approved in a research lab, it still gives enough information to provide you with fun facts and lifestyle traits. However, in no situation should you seek health-related results based on genotyping. This is one of the reasons why 23andme had to stop commercialising their health-related DNA tests in 2013.
Example of companies running on genotyping to read your DNA: 23andme, MyHeritage, AncestryDNA
When accuracy matters: Sequencing.
Thanks to research, the cost of sequencing has been decreasing drastically. The full sequencing of your genome used to take 10 years and 3 billion euros. Today, we can scan your full DNA for a bit more than 1000€ and 45 days.
Sequencing consists of reading each letter of your DNA. There are different sequencing options possible; either reading the entire DNA or only decoding chosen sequences of importance. Going back to the book analogy, this technique translates to transcribing either the entire book or only specific chosen paragraphs.
In opposition to genotyping, reading each paragraph enables the identification of any typos. Comparing your DNA to a reference DNA enables the detection of either identical words, slight changes, or bigger changes. Using current scientific knowledge, scientists interpret the meaning of these variations. They use this scientific evidence to give you information about ancestry, fitness abilities, or health predispositions in a much more contextualised and accurate way. While it may be less relevant for applications like ancestry, it is crucial when your test is health-related.
Once your DNA is decoded, it is easy to analyse it again and find more information. This is because you might read a full paragraph and discover a keyword you had never seen before. But it is always a matter of time before an explanation arises. This is what fuels research and makes sure that your understanding of the book evolves as general knowledge grows. With the constant evolution of science, updates are available with sequencing. There is no limit when it comes to looking for variations, but their interpretation and results still depend on current scientific knowledge.
Example of companies running on Sequencing: Hyperion Care, Circle DNA, Nebula Genomics, Dante Labs.
Genotyping or sequencing, which technology to choose?
Which method to choose depends on your needs. There are many DNA test companies using genotyping because of its low-cost and rapidity. With sequencing becoming a well-developed method, other companies saw the opportunity to offer more information, although at a higher cost and with a longer process. Genotyping allows easy access to your genetic information for an affordable price, although access to fresh new information is limited and only possible through extra tests. Sequencing is more of an investment in time as more and more genetic marketplaces launch apps to plug and play with your DNA online. It ensures that you will hold the complete genetic data and have access to all that is yet to come genetics apps and re-analysis.
So, what does Hyperion offer?
Hyperion offers exome sequencing. The exome is all the genes that code for proteins in your DNA and which holds 80% of health related information. In other words, we target the most important chapters of your book, providing you with all paragraphs about cancers, cardiovascular diseases, deafness, blindness and other conditions putting you and your family at risk. Unlike non-European companies, Hyperion keeps your data private and ensures medical follow-up with trained medical professionals. Read our article about the process of a DNA test to learn more.
