23andme
Posted by Sappho on July 16th, 2012 filed in Daily Life
I am about as Neanderthal as you can get. I am, 23andme assures me, in the 92nd percentile for possession of Neanderthal DNA. In practice, this means that I have a teeny, weeny bit of Neanderthal DNA, but it’s highly probably that your bit of Neanderthal DNA is teenier and weenier. (Caveats, of course, about uncertainties around the analysis of Neanderthal DNA.)
I had thought about getting some kind of consumer genetic testing for years. After being diagnosed with cancer, I decided to do it. After all, what health information could it possibly give me that would be scarier than “You have Stage 3 cancer”? I talked with my sister, and found that she had already gotten a 23andme test (her best friend from college works for the company). So, after looking over her results, I got tests done for Joel and me. Here is what I have learned.
Mitochondrial and Y DNA: Joel describes his results thus: “Another genetics nuance: I am an Etruscan remnant on my mother’s side. (Say RARE and COOL.) On the other side, I am a European mongrel from the banks of the North Sea. (Say BORING.)” My sister and I don’t, of course, know our Y DNA (for that we’d have to get a brother tested), but our mitochondrial DNA is X2b, a line that’s both rare and geographically scattered (though more common in the Orkney Islands and among the Druze). I guess the fact that we both have the same rare mitochondrial DNA proves that neither of us was switched in the hospital.
Country matching: Based on answers to a “Where are you from” survey on the site, 23andme points out sections of your DNA that match with particular countries. You can tweak the sensitivity setting, but the default is to match you with people whose grandparents all came from the same country. My sister and I match Greece and the UK – further evidence that neither of us was switched in the hospital, since all of our known ancestors go back either to Greece or to the UK. My sister’s other countries are Ireland and Albania. My other countries are Bosnia and Herzegovina, Romania, and Albania. All of these make sense, given our known Greek/English ancestry.
SNPs and Europe/Asia/Africa: I show up as whiter than James D. Watson, despite being better supplied with melanin. In fact, I also show up as slightly whiter than my sister, despite being slightly more supplied with melanin than she is. I, like Stephen Colbert, “the inescapable black hole of white people,” show up as 100% European. I apparently don’t actually have 100% European ancestry, though, because my sister, though she also shows up as almost entirely European, has a dash of Asian. The dash of Asian makes intuitive sense, given that Greece is way on the eastern end of Europe. In fact, given the corner of Europe where Greece is found, what’s more surprising is how European we both are. It turns out that this analysis of SNPs is based on matching people up with four original populations selected for geographical diversity, Yoruba in Ibadan, Nigeria; Japanese in Tokyo; Han Chinese in Beijing; and Utah residents with ancestry from northern and western Europe. It also turns out that, when people’s SNPs are matched with these four populations, genetic “Europe” is actually western Eurasia and northern Africa. So, though technically a fair number of my ancestors lived in Asia Minor (one great-grandmother came from what’s now known as Istanbul, which on the map is Asia-by-a-hair), their SNPs say “Europe.”
Global similarity: We all show up as about equally close to Northern European and Southern European DNA. This fits with our known genealogy.
Relative Finder: 23andme is said to have the largest database of potential genetic cousins. Many of them, however, signed up for the health information and then didn’t bother to monitor their inbox for genetic cousins. When my sister showed me her account, we discovered that 11 people had sent her connection requests, as possible cousins, over the course of more than a year, and she hadn’t noticed. I replied to all 11. Nine of them had apparently quit checking their inboxes. One of them has Taylors in Tennessee, and I have Taylors in Kentucky, so maybe we’re related, but we haven’t found the connection. The other has family connections with Thessaloniki, Kozani, and Istanbul, like me, and, after I supplied her with what family information I have on my father’s side, she thinks she’s found a connection. I sent messages to a few possible cousins and have heard back from one. She turns out to be a 3rd cousin once removed, related through my Hawley line. She has a family tree on ancestry.com that traces that line farther back than I have it.
Health information: I have little to lose in relating my risks, because, hey, I have cancer! That’s already a pre-existing condition. My sister, though, doesn’t yet have any pre-existing conditions, so, though I think there are laws in place limiting how 23andme’s information can be used, I’ll refrain from giving you the full scoop. What I can say is that you get a lot of genetic health information, but much of it is from experimental – from studies that haven’t been replicated yet. 23andme clearly identifies which information is solidly established and which is still experimental, and lets you print out a summary of the established information for your doctor.
It turns out that the one health condition that my sister has already experienced (and will never experience again – it was a pregnancy/childbirth complication) is one for which she shows up as having an elevated risk, but one that’s an experimental finding, not yet replicated. I, on the other hand, show up as at elevated risk for ovarian cancer, also based on an experimental finding. I have endometrial cancer that spread to the ovaries, rather than ovarian cancer, but I know that the two tend to be genetically related, so the finding is interesting, particularly since it turns out that my sister didn’t get my ovarian cancer gene (and I didn’t get her childbirth problem gene). My sister is also at somewhat elevated risk for a condition that we know my mother had on one occasion (but I didn’t inherit that gene), and we’re both at elevated risk for a condition my grandmother and great-aunt had. We’re also at elevated risk for a couple of conditions that no one in our family has had, but which are so rare that our elevated risk amounts to a slightly increased risk of being struck by lightning. And we’re at decreased risk for a lot of things. In particular, my sister, my husband, and I are all at reduced risk of getting Alzheimer’s. Yay!
One interesting genetic finding is that I have pseudocholinesterase deficiency. This genetic trait may or may not be at a clinically significant level, but I added it to my MedicAlert information just to be safe, just in case anyone ever wants to give me succinylcholine.
Oddly, my husband shows up as at reduced risk of having asthma, although he does in fact have asthma. On the other hand, he shows up as at increased risk of having bipolar disorder, and does have bipolar disorder.
Traits: I probably have brown eyes. My sister probably has blue eyes. My husband probably has brown eyes. For the most part, we do show up as being likely to have the physical traits that we actually have. An exception is that my sister shows up as being predisposed to have curlier hair than me, and actually both of us have fairly straight hair. I guess some other genes are straightening her hair out.
One thing to note here is that both my sister and I are at average (neither increased nor reduced) risk of obesity. This interests me, because, out of nine siblings, seven of us have reached middle age, and none of us are obese. In fact, not only aren’t we obese, but in general we aren’t even overweight (if any of us is at all over normal BMI, it can only be slightly, and I’m sure the majority of us are well within range). This makes us thinner than the average middle-aged American, as a family. Given our genetic results, I guess this must be a triumph of environment over genetics; for whatever reason, our environment predisposed us to eat and exercise to the degree needed to stay thin. Unfortunately, I don’t know how to bottle the environmental factor that had this effect.