The DNA dilemma

Science journalist—and my fellow mental_floss alum—Mary Carmichael is thinking about taking an at-home DNA test. But, before she goes all the way, she's doing some major background research: Holding up a spotlight onto the business of DNA reports, and examining what these tests can (and can't) tell you, and how reliable they really are.

Mary's put together a fascinating series that's running all this week. On Friday, she'll weight the benefits and detriments and make her choice. Highly recommended reading! The excerpt below is from a series of interviews and analysis looking at what you can actually learn from a DNA test.

NOT WHAT YOU MAY EXPECT

Steven Murphy

physician specializing in personalized medicine and vocal DTC critic

"I have seen probably more patients with these types of tests than just about any clinician out there, so I can tell you what the patients ask and what I tell them. (1) You will not learn what you will die from. In fact, most tests won't tell you, whether ordered via Amazon or through your doctor. (2) You will not learn what diet is right for you. We do know some people may benefit from some types of diets to lower cholesterol and lose weight, but the science to accurately predict genes and diet is not ready to bring to market. (3) You will not learn if you are of the lost tribes of Israel. The J Haplogroup analysis you get is only a small window into heritage.

The results for positive carrier tests are just as valid as those ordered by a doctor in some instances. But they may be better at ruling in than ruling out. If it says you are not a carrier, don't trust the results. If it says you are, you can double check with a doctor. You may learn you carry a rare mutation putting you at significantly increased risk of breast or ovarian cancer. Are you ready for what to do with those results if you had them?"

Mary's take: Murphy may have seen patients asking "what they'll die from" based on a DTC test, but I myself wouldn't ask such a silly question. I appreciated his concern that I might not be ready to find out about BRCA, the breast and ovarian cancer mutation, and so, apparently, did the test makers. Some potentially life-altering results are "locked" in many DTC reports. You're supposed to specifically decide you're ready to see them before you actually do. Mirabile dictu, I started to believe I was reaching a consensus among my contributors: you won't get much good out of the test if you don't actively think about the results.