Millions of people have taken consumer DNA tests and received their results online. In fact, this summer Ancestry® surpassed 18 million members, building on the world’s largest consumer DNA network.

These simple-to-take, saliva-based tests reveal your possible ethnic origins, connect you to distant relatives, help you find ancestors, and uncover new details about your family history.

But how much do you know about these tests?

Barry Starr, Ph.D., and Director of Scientific Communications at Ancestry, the global leader in family history and consumer genomics, shares 5 things every consumer should know about DNA tests:

1. Your DNA is different from your brothers’ and sisters’, even though you have the same parents.

The particular mix of. DNA you inherit is unique to you. You get half of your DNA. from each of your biological parents, as did each of your brothers and sisters, but all your siblings don’t get the same half.  This means your brother or sister will have different DNA than you, most likely resulting in their own unique ethnicity estimate. Their DNA can reveal unique parts of your family’s story.  This is why it is so useful to have your brothers and sisters tested — you get a more complete picture of your family’s history with each added sibling.

2. Your DNA results don’t always fall within modern country borders.

Because of changes in country boundaries and migration patterns throughout history, people’s ethnicity results do not always line up with modern-day countries. For example, people from modern-day Austria may have DNA from our Eastern Europe & Russia region because of the Austrian-Hungarian Empire that split in the early 1900s. Similarly people with roots in northern England may have a surprising amount of Scotland in their results because of close ties these regions have had over the centuries. This means that even if you trace your family history back to a specific, current country, your DNA results may show you’re connected to a region outside that country’s current borders.

3. Your DNA. doesn’t change, but the methods used to analyze it do.

Consumer genomics is a new and evolving industry, and scientists are constantly revealing new ways to learn about your history through DNA. Like many other companies, Ancestry analyzes your DNA by comparing it to the DNA of groups of people whose families have a long history in a particular region. These people make up the AncestryDNA reference panel. Updates to your results come from advances in the algorithms used to analyze your DNA and/or increases in the size of the reference panel itself. For example, in 2018 Ancestry® added new samples to its reference panel making it 5X larger. This led to a new update which allowed members to connect to even more regions around the world. As consumer DNA networks grow and science advances, consumers can expect many companies to add to and update their reference panels, resulting in more comprehensive and precise results.

4. You own your personal genetic data.

Consumer DNA companies are at the cutting edge of genomic science and have a responsibility to set the bar for industry innovation. For that reason, Ancestry, along with several other companies, partnered with the Future of Privacy Forum to release the Privacy Best Practices for Consumer Genetic Testing Services in 2018. These guidelines are the first of their kind for the industry and set a self-governed policy framework for the collection, protection, sharing and use of data collected by consumer genomics companies. You should read the privacy policy of any company you test with to understand how your data is being protected — as well as how the policy aligns with the FPF Best Practices.

5. You must go beyond DNA to get the complete picture of your family history and origins.

Your DNA tells only part of your story, because we inherit only half of each parent’s DNA. This means that not all your family’s details can be read in your DNA. To fill in the gaps, you can build a family tree and use historical records to discover family photos, documents with original signatures, and census information collected at your ancestor’s doorsteps. Going beyond DNA can reveal rich context and give a fuller picture of your family history.

Barry Starr, Ph.D., Director of Scientific Communications at Ancestry, is a science communicator and educator with a passion for genetics.