Genetic testing kits you can do at home seem to be on many holiday wish lists this year; one even landed on Oprah’s list of favorite things. The affordable kits, like those from 23andMe and ancestry.com, can scan your genes from a spit sample. But it’s important to know what they can and cannot do when it comes to teaching you about your medical well-being.
You won’t find out everything about your genes. Most genetic testing companies don’t actually sequence all three billion base pairs of your entire DNA. They generally focus on certain sections where there is stronger information about what genetic changes mean.
Don’t expect to learn if you’re going to get cancer. Any type of genetic testing, from the consumer-based kits that anyone can buy to the versions that doctors order, can only glean so much information from your DNA. Medical conditions like cancer and heart disease are complex and not likely to be traced to a single aberration in DNA.
You’ll learn more about where you came from. Much of the appeal of getting your DNA sequenced is learning about how much of your genome you share with people from all over the world. It is possible to discover a surprise Scottish heritage, for example, or even that you’re descended from George Washington.
Genetic sequencing is particularly good at this, since it can find common DNA denominators among people of different racial and ethnic origins. Some people have even used genetic ancestry testing to find biological parents or lost relatives.
Your DNA may not be as private as you think. Consumer testing companies will assure you that the genetic information they uncover from your saliva sample is protected. And it is, to some extent: They can’t share your genetic information without your permission. But there’s an exception. Some companies note that if law enforcement requires them to relinquish genetic data, the companies will comply.
If you want to learn from your DNA, share your test results with a doctor who is knowledgeable about both genetics and the disease that you’re interested in.
