In the last few years, at-home genetic tests, like those offered by 23 and Me and Ancestry.com, have become very popular holiday presents. A glimpse into one’s family history can seem like a deeply meaningful and special gift. Indeed, the kits are marketed this way, with emotional testimonials from users about how discovering unsuspected ethnic heritage or distant relatives changed their lives for the better. But before taking such a test, it’s important to fully understand what the tests can actually tell you, and what pitfalls may lurk for the unsuspecting.
How do At-Home Genetic Tests Work?
The most popular at-home genetic kits all work in a similar way: you collect a sample of your DNA with the gear included in the kit. With some kits, you spit into a tube; with others, you swab the inside of your mouth. You then pack up the sample and send it off in the provided envelope or box. Several weeks later, you receive a report that tells you about your genetic heritage, which may include information about parts of the world where your ancestors came from, and traits and even diseases that you may have a genetic marker for.
It’s important to understand that these reports are generated by comparing your DNA results to the results from millions of others contained in proprietary databases owned by the testing companies. The results only reflect comparison to the others in that particular database, and the makeup of the database can affect your results. For example, some ethnic groups are better represented than others, so the database is more likely to recognize your genes that are associated with one group, but it could miss the connection to another group.
Because each company uses its own databases, you can actually get somewhat different results, depending on which company’s test you take. So the first factor to consider before taking the test is that the results are not necessarily definitive and may reflect built-in biases of the data that your results are compared with.
Also, because the databases are proprietary, the companies do not share results with each other and there is no authority that certifies the accuracy of the information. You are essentially taking the testing company’s word that the results are what they say they are.
Before you spit into that tube and send your DNA off for analysis, you may want to consider some other factors:
You May Uncover Hidden Family Drama
As genetic tests have become more widespread, stories have come out about unwelcome family discoveries. In earlier generations where pregnancy outside of marriage was frowned on, families often hid these pregnancies through informal adoption with friends, other relatives, or grandparents raising a grandchild as their child. Sometimes these children lived their entire lives without knowing their true origin.
Through at-home genetic tests, people have inadvertently discovered that their father was not their biological father, or a sister was actually their mother. Information that was expected to bring relatives closer has, in some cases, caused division and strife. You should understand that you run the risk of learning something you didn’t really want to know, or that other family members had kept private.
You May Learn Alarming Health News
Some of the tests give information about possible genetic predispositions to health conditions, such as heart disease, cancer, and Alzheimer’s disease. You may also find out that you are a potential carrier for a condition that does not affect your health, but could be passed on to children. This can be upsetting or frightening news for some people.
Again, it is important to remember that these tests are not definitive. They are not saying that you are doomed to die from cancer or Alzheimer’s. Most diseases are not purely genetic, but are a combination of genes, environment, and lifestyle choices. A genetic marker for a disease can tell you that you are more likely to develop the condition later in life, but not that it is inevitable. In fact, learning of genetic predispositions has motivated many people to make lifestyle changes, such as losing weight or quitting smoking.
Make sure you read the report carefully, including all explanations of the health-related results and what they mean. You may also consider professional genetic counseling to further explain and clarify your understanding.
Your Test Results May be Put to Uses Beyond Your Control
Before taking an at-home DNA test, read the privacy and disclosure information thoroughly. Each company has different policies for how your results are retained, and what they may be used for beyond generating your personal report. Depending on the company, they may be employed for scientific and medical research and possibly even law enforcement and forensic searches. Like zip code and credit databases, companies may one day sell information from DNA databases to marketers or even health and life insurers.
It’s important to understand that your information will be on file permanently and that it may be used in the future in ways that the company currently says that it won’t be. Corporate policies can change with time, and if a company is bought out, its databases can become the property of new owners who may not be bound by the same agreements. Make sure you read any future communication from the company that may be explaining new policies and offering you a limited opportunity to opt out and have your data destroyed or removed from the database.
As more people use the various genetic testing kits, the databases grow more detailed and information more personally identifiable. Even if you decide not to be tested yourself, if enough of your relatives take the tests over time, you can be nearly as identifiable as if you took the test yourself. The suspected Golden State killer did not have his own DNA in a database, but his relatives did.
There are also matters of data security. Just as credit card numbers are hacked from computers thought to be secure, it’s possible that in the future there may be news stories of genetic databases being hacked and the data sold to unknown buyers for unknown uses. There are currently policies being proposed to add strings of identifying data unique to each testing company to users’ genetic profiles so that the source of the information can always be traceable. But these proposals are preliminary and there hasn’t been any agreement from various companies to do this.
Most people get nothing but enjoyment from taking these tests, and these risks have not materialised for the vast majority of users. However, it is important to make a fully informed decision before proceeding, lest the warm holiday glow give way to cold and unpleasant reality down the road.