DNA and Me

Betsy, this one's for you :)



I've been tracing my family tree for years and always wondered what I didn't know about my ancestry. Ads for DNA testing caught my eye years ago, but the price near $300 was prohibitive.

Well, last year 23 and me dropped their price below $100 so I decided what the heck and bought a kit online. When it arrived, I set it aside for over a month before I decided to commit to the testing. I was a little taken aback by all their warnings and disclaimers about learning things you might not want to know about yourself, particularly in the health department. I didn't expect any surprises like your Dad isn't really your Dad, because we weren't that kind of family, as far as I knew.

I'm not sure what I expected to learn, really; I was just curious what I might find out. So I spit in the test tube. A lot. And then some more. It really takes a lot of saliva to test your DNA, and it takes 5-10 minutes to get enough gathered to mail off in the handy little kit.

Ancestry.com has a DNA test kit, but I don't know much about it, and I chose 23 and me only because they dropped their price first. It takes a really long time to get results, and in the interim, you can participate in their studies by answering lots of questions about your family and your health. They go on forever and can get a little tedious, but they supposedly aid in research so I volunteered lots of information while I waited for my results.

Here's what I learned, and honestly, I knew a lot of it, but there were a few surprises.

On the ancestry side, I learned I have 2.6% Neanderthal DNA, which maybe explains my great big nose and my gentle nature. Did you know there are current anthropological theories that suggest Neanderthals were killed off by their more aggressive and intelligent competitors Homo Sapiens? It seems that the Homo Sapiens might have kept some Neanderthal women as their spoils of war, and  so some of us have remnants of those ancestors in their DNA. I learned that my Haplogroup is U5, and that I don't really have a good enough grasp of genetics or DNA to really figure out what all this means, but I do like the sound of the word Haplogroup. 

Here's what the web site says about U5:   U5 is one of the oldest haplogroups in Europe. It probably arose when modern humans first moved into western Eurasia from the Near East about 40,000 years ago. As the earliest members of U5 spread across the new territory they would have encountered some oddly familiar inhabitants; the Neanderthals, a close relative of Homo sapiens, had been living in the region for more than 200,000 years. But the Neanderthals proved no match for the new arrivals - by 28,000 years ago they were gone, driven extinct by either competition or outright warfare. The 9% of Europeans who carry the U5 haplogroup today can trace their maternal ancestry directly back to those early colonizers of Europe.

These facts made me sad, to think how little the world has changed.

I also learned that my ancestry is predominantly European, 99.5% in fact, which doesn't surprise me since my genealogy research shows that I am Irish, English, Scottish and French. My DNA shows that I am 32% British and Irish, and that about 50,000 years ago, my ancestors migrated from Africa into Europe. My research shows me that my more recent ancestors emigrated to North America from England in the early to mid 1600's, in search of opportunity and religious freedom on my mother's side, and that the potato famine drove my father's family to cross the Atlantic Ocean. I find it fascinating to think of the vagaries of chance and circumstance that caused my ancestors to migrate in search of a better life, and more fascinating still to marvel that any of us made it to this point in time at all.

I learned that huge glaciers caused groups of people to be isolated and trapped in regions of Europe, and that the mutation for blue eyes began in one of those isolated groups. My genotype is GG:

Three studies have found that blue eyes most often result if a person has two copies of the G version of this OCA2-controlling SNP, suggesting that the genetic origin of the trait can be traced back to a single point in human evolution. The authors of one of the studies hypothesize that the mutation event that created this version of the SNP happened somewhere around the Black Sea between about 6,000 and 10,000 years ago. During that time generations of migrating farmers gradually carried agriculture from the Near East to northern Europe, where blue eyes are most often found. These same researchers found that blue-eyed individuals from the Mediterranean (five from Turkey and two from Jordan) also have the G version of this SNP, suggesting that blue eyes the world over can be explained by variation in this one SNP. 

What's an SNP you might ask? It stands for single nucleotide polymorphism, or snips, and there's a wonderful explanation here if you are really curious. They are not so much about genetic variation as they are biological markers for important things like drug response. I wish I could tell my old doctor that my sensitivity to and side affects from certain drugs was not imaginary, it was due to my snips.

There are lots of charts and graphs to look at but my attention span isn't what it used to be for these things. I learned mostly, that maternal DNA doesn't tell you as much as paternal DNA, and that if I really want to know more, I have to get my brother to spit in a test tube too, since my Dad is no longer with us. Women even get the short end of the stick with genetic testing. Sheese. 

On the health side, I learned that I already knew I was at increased risk for heart disease, psoriasis and arthritis, no surprises there. What I didn't know, and what I was most afraid of, was that I do NOT have an increased risk for Alzheimer's, macular degeneration and diabetes, all of which have plagued my relatives. Best of all, I do not have an increased risk for breast cancer, which was on top of my worry list.

In other not surprising news, I learned I have an increased risk of alcoholism, a very high risk of heroin addiction, I'm slow to metabolize caffeine, and that my genotype AA make me slightly smarter than the average person, slightly more likely to overeat and if a smoker, likely to smoke more than average. That explains the two pack a day habit I had in my twenties, and my addictive personality in general. I guess I've been fighting my nature for a long time now, so those extra IQ points must be worth something.

There is an overwhelming amount of information available about my DNA, and I'm still trying to digest it all. Genealogically,  23 and me will notify me if there are any close matches to me in the database. So far it's just 3rd to 5th cousins that have shown a match and I've exchanged genealogy information with one man, but our lines diverged over a hundred years ago, so I doubt we'll be getting together to reminisce any time soon.

So, to conclude, am I glad I did the testing? I guess so. It's worth twice the price to stop worrying about Alzheimer's and Breast Cancer, and even more so to know I need to pay better attention to my heart health* and to never try heroin :)  In the future, I like to think that this type of genetic testing could be useful in determining and minimizing risk factors and for better tailoring of medications to individuals based on their genetic makeup, not the pharmaceutical companies' revenue-based recommendations. Maybe someday.....

* easier to do thanks to team Team S.J.G.R. over at Dr. Kim's place.