As genetic testing expands into a mail-order industry, it’s getting easier for consumers to learn about their ancestry, inherited traits and individual health risks. But what are we supposed to do with this information? How do we interpret it without a doctor’s help? Joel Eissenberg, PhD, a biochemistry and molecular biology professor at St. Louis University, has investigated this issue. Here, he discusses the impacts of removing doctors from the link between patients and potentially sensitive health information.
What exactly can people learn from DNA testing tools?
Joel Eissenberg: With genome sequencing, you can discover if you’re a carrier for sickle cell disease, cystic fibrosis, Tay-Sachs disease or any condition for which we know specific genes are affected. If you’re a carrier, your genome contains one copy of that mutation and you’ll risk passing it onto your child. You might want your partner to get tested before you decide to have children. When Angelina Jolie found out she had a mutation in the BRCA1 gene that gives her a 60 percent to 90 percent chance of breast cancer, she had a bilateral mastectomy.
However, for many common traits, the quality of clinical data is poor. A lot of people are interested in their risk of Alzheimer’s, heart disease, diabetes and stroke, but unfortunately, the ability to predict risk of these conditions based on genetic sequence is poor. If concerned about heart attack risk, probably the best things to do are to watch diet and weight and stop smoking—and no one needs a genetic test to tell him that.
Are there genetic testing companies to be wary of for any reason?
JE: Some companies offer nutrition advice based on genetic testing, and I find that kind of sketchy. If someone is going for advice like, ‘Should I be eating whole foods?’ Yeah, he should be—regardless of what genetic tests say.
Is genetic testing empowering or harmful for consumers?
JE: I’d go with somewhere between empowering and neutral. What power does it really give you? Not a lot, in most cases. Occasionally, if you find out you have a high risk of certain cancers, there are steps to reduce your chances of dying of the disease. I’d err on the side of distributing this information if there’s no clear indication that it’ll cause harm. I’d also advise talking to a physician before getting tested. Consumers should be prepared for unexpected or adverse information, because it’s not rare.
When will the technology be able to provide more info on diabetes and other conditions that interest many people?
JE: I’d be surprised if we don’t have a markedly more reliable clinical database for many DNA sequence markers within 10 years—easily within our lifetime. Because the costs have plummeted, the pace at which medical information is accruing, especially DNA sequence information, is just breathtaking.