Diagnostic medical laboratories may sequence DNA genetic tests correctly, but there are issues with how companies analyze the information
In 2017, some 12 million people paid to spit in a tube and have their genetic data analyzed, according to Technology Review. Many companies offer this type of DNA testing, and each of them works with one or more clinical laboratories to get the actual sequencing performed. For example, Ancestry.com, one of the largest direct-to-consumer genetic data testing companies, works with both Quest Diagnostics and Illumina.
In the case of Quest Diagnostics, the clinical laboratory company does the actual sequencing for Ancestry. But the analysis of the genetic data for an individual and its interpretation is performed by Ancestry’s team.
There are critics of the booming direct-to-consumer genetic testing business, but it’s not due to the quality of the sequencing. Rather, critics cite other issues, such as:
- Privacy concerns;
- How the physical samples are stored and used;
- Who owns the data; and,
- That this branch of genetics is an area of emerging study and not clearly understood.
What Does All That Genetic Data Mean?
The consumer DNA testing market was worth $359 million dollars in 2017 and is projected to grow to $928 million by 2023, according to a report from Research and Markets. Those numbers represent a lot of spit, and an enormous amount of personal health information. As of now, some one in every 25 adults in the US has access to their genetic data. But, what does all that data mean?
The answer depends, in large part, on who you ask. Many reporters, scientists, and others have taken multiple DNA tests from different companies and received entirely different results. In some cases, the sequencing from one sample submitted to different companies for analysis have rendered dramatically different results.
It’s All About the Database
Although some people purchase kits from multiple companies, the majority of people take just one test. Each person who buys genetic analysis from Ancestry, for example, consents to having his/her data become part of Ancestry’s enormous database, which is used to perform the analyses that people pay for. There are some interesting implications to how these databases are built.
First, they are primarily made up of paying customers, which means that the vast majority of genetic datasets in Ancestry’s database come from people who have enough disposable income to purchase the kit and analysis. It may not seem like an important detail, but it shows that the comparison population is not the same as the general population.
Second, because the analyses compare the sample DNA to DNA already in the database, it matters how many people from any given area have taken the test and are in the database. An article in Gizmodo describes one family’s experience with DNA testing and some of the pitfalls. The author quotes a representative from the company 23andMe as saying, “Different companies have different reference data sets and different algorithms, hence the variance in results. Middle Eastern reference populations [for example] are not as well represented as European, an industry-wide challenge.”
The same is true for any population where not many members have taken the test for a particular company. In an interview with NPR about trying to find information about her ancestry, journalist Alex Wagner described a similar problem, saying, “There are not a lot of Burmese people taking DNA tests … and so, the results that were returned were kind of nebulous.”
Wagner’s mother and grandmother both immigrated to the US from Burma in 1965, and when Wagner began investigating her ancestry, she, both of her parents, and her grandmother, all took tests from three different direct-to-consumer DNA testing companies. To Wagner’s surprise, her mother and grandmother both had results that showed they were Mongolian, but none of the results indicated Burmese heritage. In the interview she says that one of the biggest things she learned through doing all these tests was that “a lot of these DNA test companies [are] commercial enterprises. So, they basically purchase or acquire DNA samples on market-demand.”
As it turns out, there aren’t many Burmese people taking DNA tests, so there’s not much reason for the testing companies to pursue having a robust Burmese or even Southeast Asian database of DNA.
Who Owns Your Genetic Data?
As is often the case when it comes to technological advances, existing law hasn’t quite caught up with the market for ancestry DNA testing. There are some important unanswered questions, such as who owns the data that results from a DNA analysis?
An investigation conducted by the news organization McClatchy found that Ancestry does allow customers to request their DNA information be deleted from the company’s database, and that they can request their physical sample be destroyed as well. The author writes, “But it is a two-step process, and customers must read deep into the company’s privacy statement to learn how to do it. Requests for DNA data elimination can be made online, but the company asks customers to call its support center to request destruction of their biological sample.”
Another concern is hacking or theft. Ancestry and similar companies take steps to protect customers’ information, such as using barcodes rather than names and encryption when samples are sent to labs. Nevertheless, there was an incident in 2017 in which hackers infiltrated a website owned by Ancestry called RootsWeb. “The RootsWeb situation was certainly unfortunate,” Eric Heath, Ancestry’s Chief Privacy Officer, told McClatchy. He added that RootsWeb was a “completely separate system” from the Ancestry database that includes DNA information.
What We Don’t Know
The biggest pitfall for consumers may be that geneticists don’t know very much about DNA analysis. Adam Rutherford, PhD, is a British geneticist who interviewed for the Gizmodo story. He said that the real problem with companies like Ancestry is that people have a basic, fundamental misunderstanding of what can be learned from a DNA test.
“They’re not telling you where your DNA comes from in the past. They’re telling you where on Earth your DNA is from today,” Rutherford told Gizmodo.
Science evolves, of course, and genetic testing has much evolving to do. The author of the Gizmodo piece writes, “It’s not that the science is bad. It’s that it’s inherently imperfect.” There aren’t any best-practices for analyzing DNA data yet, and companies like Ancestry aren’t doing much to make sure their customers understand that fact.
Nevertheless, issues surrounding genetic testing, the resulting data, and its storage, interpretation, and protection, continue to impact clinical laboratories and anatomic pathology groups.