Over the past few years we’ve looked at two DNA testing services: AncestryDNA and Family Tree DNA. 23andMe offers a third variation on the theme. Whereas the first two are focused on matching you up with those with whom you share DNA (aka your relatives), 23andMe has a broader mission.
The Mountain View, Calif.-based company both determines your ancestry (which includes matches of folks you share DNA with on their database) and offers testing for genetic health risks.
These include Parkinson’s disease, macular degeneration, late-onset Alzheimer’s disease as well as 40 other conditions. In addition to health risks, they also provide details on any number of traits, including your genetic predisposition for being above or below average weight, hair color, ability to detect asparagus odor, etc. (Presumably most of these things you’re familiar with!)
The test is easy to administer. All you do is provide them with a sputum sample.
My co-writer, Rob Kay, participated in the testing and said he liked that 23andMe delves into areas that other services don’t touch. For example, on the ancestry side, it gives you detail about your maternal and paternal lines. Rob learned his maternal haplogroup is K1a1b1a, a lineage that traces back to a woman who lived approximately 4,500 years ago. 23andMe even tells you how much Neanderthal DNA you have. (For better or worse, Rob scored low on this count).
What really separates 23andMe from the others, and is most controversial, is its genetic health risk report.
It reports whether you carry DNA variants that, according to research, are associated with a higher risk of a disease. In Rob’s case (permission given for disclosure), he carried a “variant in the DFG gene for macular degeneration.” Rob said he’s trying to prevent macular degeneration by eating goji berries, which his friend, ophthalmologist Malcolm Ing, founder of Hawaii Vision Clinic, highly recommends.
Rob’s actions go to the heart of interpreting the 23andMe health risk reports. Knowledge is power.
According to Bradley Willcox, M.D., director of research at the Department of Geriatric Medicine, John A. Burns School of Medicine, just because you test positive for a mutation in the genes to develop a disease such as late-onset Alzheimer’s, it doesn’t mean “you’re doomed.” “Lifestyle factors such as diet, exercise, not smoking, moderate alcohol use, etc. play a huge role in prevention,” Willcox said.
“Carrying a genetic variant for a disease,” he told us, “might increase risk by only single-digit percentages.” If you’re worried, he advises that you visit a genetic counselor who can order more comprehensive tests. (He suggests one way to recognize whether you have a predisposition for a disease is to look at your family history).
Does he think the health risk tests from 23andMe are useful?
“Most definitely,” he replied.
Willcox says that if you know that you have a genetic predisposition for a disease, even though it may be unlikely you’ll get it, you can make changes in your life to counteract risk. On the flip side, says Willcox, even if you test negative for a genetic risk for a disease such as Alzheimer’s, there may be other genetic variants not tested for that could further increase or decrease risks.
Among the genes he thinks important for testing are the variants for the FOXO3 gene (aka human longevity gene), which he studies with the National Institute on Aging-funded Kuakini Hawaii Lifespan Study. Willcox and colleagues discovered that people who have the protective gene variant have double the odds of living to 100.
Even if you don’t have the “longevity” variant of the FOXO3 gene, he says if you eat and exercise right, you can still markedly increase your odds of becoming a centenarian.
The bottom line: After sampling three different DNA testing services, we think 23andMe is a great option if you’re interested both in ancestry and genetic health risks. 23andMe offers two options: Health + Ancestry ($199) and Ancestry ($99).
Mike Meyer is chief information officer for Honolulu Community College. Reach him at mmeyer@hawaii.edu.
