About a year ago, my husband and I did a 23andme DNA kit to find out more specifics about our genetic heritage. We paid the extra to get health information as well. The process was very easy. The company sends you a plastic tube. You spit into the tube and send it back via self-addressed pre-stamped packaging. Then in a few weeks, you receive an email invitation to view your results online.
Once you have your results, you can participate in surveys about your health and personality that they will then use to create more genetic information for future users. You can also opt to connect with relatives identified by 23andme and their own spit (not everyone chooses to do this; if they want to remain private, their identity is not revealed). I have nothing to hide, so I chose to do this. With relatives, either known to you or strangers, you can view your DNA results side by side to compare which is interesting. For example, I can view my results next to my husband’s to see that he’s more British than I am or that he’s less prone to move in his sleep than I am or I have a slightly elevated risk for celiac disease and I freckle more easily. Obviously some of these factors are things I don’t need to pay $200 to know.
My 23 and Me DNA results back raised a few questions for me, especially when I compared to my relatives. Alas, my choice of a B.A. rather than a B.S. degree left me lacking in some of the fundamentals. I figured out a couple of them on my own, but I am no Watson or Crick, so I checked in with a couple of friends with better biological chops than I have.
My Initial Observations
A niece and a half-sister are the same, genetically. 23andme guessed that my niece was my half-sister, and thinking about it, that is probably mathematically correct. A niece and a half-sister would both be a 25% DNA overlap. Because my niece is only 3 years younger than me, the system assumed based on our ages that we were half-sisters.
The smaller percentages don’t always match up to your parents. I had two results that were confusing to me. First, I’m 4% Iberian according to my results, but my dad has no Iberian, and my mother only has 0.4% Iberian. Since my DNA comes from both parents (49.9% from my dad, 50% from my mom), how can I be more than 0.8% Iberian? My theories were:
- The test is off (e.g. confidence levels, etc.)
- It’s a mish-mosh of the uncategorized “broadly Southern European” DNA from both parents.
The really really small percentages can be kind of random, maybe due to rounding. I’ve got 0.1% Middle Eastern & North African, but neither of my parents has any.
My hypothesis about the doubling of one parent’s stat in my own seemed confirmed by the Italian percentage. I’m 2.5%, and my mother is 1.2%. So, does this mean I got ALL her Italian genes? It could explain my fantastic Jersey Shore accent.
What I found out from my friends was that 1) yes, there are huge error bars in the confidence levels, and 2)
Me: OK, so reading this, it’s likely that my Iberian result differs so greatly from my parents because theirs is not specified, but just in the broader category of Southern European. The confidence levels are greater when sub-categories are assigned.
Smarter Friend: Yeah, that’s within the range of stochastic variation. I noticed that they occasionally, refine the results as more sensitive tests are developed. On the first report they send my mom had [specific] alleles, then she didn’t (which was a disappointment). What your Neanderthal percentile? In the grand scheme of things that’s the one that matters.
First of all, the Neanderthal variants thing was a shocker, like finding out that I was the offspring of hill people. So, I have 282 genetic markers associated with Neanderthal variants, more than 57% of respondents, but it’s less than 4% of my DNA. That’s a lot of numbers. It’s fewer than my husband has. In their testing, I had no Neanderthal variants associated with height, straight hair, back hair (or one can assume straight back hair) or sneezing when I eat dark chocolate. So, I guess that’s a relief.
Looking into it, though, there are actually positives associated with Neanderthal DNA. Some tests show that those with specific Neanderthal DNA variants have superior immune systems. Since Neanderthals mated with humans as recently as 50,000 years ago, it’s theorized that their superior immune systems helped humans weather the harsher weather outside of Africa as they migrated northward.
Skeletons in the Family Closet
I didn’t have any of these, but before you submit your kit, there’s a disclaimer that you might find out things that you didn’t know about your biological relatives, things you may find upsetting like parental infidelity or incest or who knows what. A few friends in an online forum were discussing their results and several had unexpected discoveries like that about siblings, parents or grandparents.
It’s definitely a caution worth considering, especially since a lot of families have done these tests together or bought them for relatives as a gift.
With our focus on families in the church, a lot of Mormons have done these tests.
- If you’ve done a genetic test, were any of your results surprising?
- If you haven’t done a test, do you want to do it? Why or why not?
- Do you think it’s a good gift or is the risk of family trauma too great?