Saturday, October 11, 2008

What’s in my genes? Results from 23andme

My DNA test results arrived much sooner than I expected. They tell you six to eight weeks, but it was more like two or three. The company that I chose for the test, 23andme, recently dropped their price to only $400, making it much more affordable. (By the way, I paid the original $1,000 price, but they generously refunded the difference--a hint that they care about good customer satisfaction).

I hope to post much more about this as I get time to analyze my data, but meanwhile enough customers are out there now that it's possible to get a sense for the direction this technology is headed. Mark Fletcher is an early user who posted his experiences, and there are several others who have even posted their entire results on line. One of my readers suggested I check out Promethease, a Windows/Mac program that will run through your results and tell you everything that's known about your SNPs. Since my test shows 500,000 SNPs, there is a lot to analyze and I'll need as much help as I can get.

So let's open the envelope, please, and tell me the results!

First, no surprises on my ancestry. Although I found out through the $99 Genographic Project's test that my grandmother is likely descended from native Americans, no such traces exist on either my mitochondrial or Y-chromosomal DNA. I am about as pure-blooded a north European as the test shows it is possible to be. For example, here's a distribution of the people who share my haplogroup, H1*, the one I got from my mother.

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On my father's side, R1b1c9, the results are similar:

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Note that these results are consistent with the very different conclusion from my Indian grandmother, who gave me 1/4th of my overall genes, but not the ones from this test. Remember, my mitochondrial DNA comes exclusively via my mother, just like my Y-chromosome DNA comes exclusively from my father. Since Grandma (a female) had no Y to pass down, my Y comes from my father and grandfather. Similarly, my mitochondrial DNA is 100% from my Lithuanian mother's side (as you can clearly see from the diagrams above).  All the more reason to test your own grandparents while they’re still alive.

Okay, so that’s ancestry.  What about the rest?  23andme provides some basic analysis on (as of today) about 90 specific genetic conditions, with varying degrees of scientific certainty or idle interest, depending on how well-studied these are.

In my case the following areas turned up good:

  • Very low chance of Parkinson’s Disease (unlike Google co-founder Sergei Brin)
  • I have the same mutation as that Jamaican Olympic sprinter!
  • No Crohn’s, no Celiac, no lupus, no gout.
  • No male infertility (hmmmm)
  • Higher odds of living to 100
  • IQ:  breast-feeding would have raised my IQ 4-5 points.  (thanks for nothing, Mom)
  • Heart disease:  lower than average risk.  (14.5 out of 100 versus 17.7 out of 100 for other white males)
  • Arthritis:  lower than normal (1.1/100 vs. 4.2)
  • Diabetes: almost no chance whatsoever of getting Type I and lower than normal odds on Type II (13 vs. 21/100)
  • Lactose tolerance:  what do you expect from a farm boy like me?

Biggest worries:  [note to insurance companies: please stop reading here]

There are many more mutations covered by the test, but these are the most relevant to me.  As you can see, the results are mixed: some “good” news, some “bad”.  But look more closely and you’ll see why I’m not sure yet if this really tells me much.  For example, I have a mutation (rs1051730) associated with nicotine dependence.  Okay, guess I better not smoke.  Same thing goes with similar mutations associated with heroin, HIV, and noroviruses:  I’m at risk.  Big deal.  My mother tells me these things even without viewing my genetic results.  Did I pay $400 for this?

Of course, if some of these results had gone the other way – and I’m less susceptible to addiction, HIV, or other preventable conditions – would that make me consider taking up different behaviors?  No, of course not.  There are lots of good non-genetic reasons to avoid these things.

I also question the reliability of some of the science.  For example, one of my mutations is associated with higher-than-normal risk of becoming obese if I eat more than 30% of my calories as fat.  That’s absurd to anyone who knows me and my eating habits: I’ve been skinny since childhood, seemingly regardless of what I eat.  But if I were overweight, I’d look at the same result with a big “aha” and think I know something revealing about myself.

So my bottom line is that although this is fascinating to somebody like me who is willing to invest the time and skeptical energy to interpreting these results, I’m not sure others will benefit much yet.  A cursory glance will tell you a few things, but it will take much work and analysis to uncover whether the results are truly interesting, or whether they merely confirm your own preconceived biases about yourself.

4 comments:

Jimbo said...

interesting details, although I must say that the details of future ailments makes me less likely to take the test.

Noticed you had some Subcontinental Indian in you on your father's side.--wassup wid dat?

Craig Fisher said...

Yes, very interesting post Richard.

Jimbo: that diagram just indicates the distribution of R1b1c9. Likelihood that Richard got his from the Indian subcontinent is low as indicated by the color there. Most likely source is indicated by the dark (black?) color.

Beth said...

the results of these types of tests are merely risk percentages - you say you "question the reliability of some of the science," because you, individually, are not prone to be overweight even though your genes predict that you are more likely to be overweight. that's the same thing as saying you've proven you're not really more likely to get in a car accident within 10 miles of your home since you just got back from a trip to the store and suffered no accident. though we've mapped the genome, that doesn't mean we fully understand what it means. the results of this mapping, currently, can only tell us about genetic disorders we've already discovered the "code" for. maybe in a few years your results can be looked at again with new knowledge, and more specific information can be found. but as it is, there really isn't a whole lot of benefit from these tests aside from sparking an interesting conversation.

Richard Sprague said...

Beth, unfortunately I agree that the major value of this test is to spark interesting conversations.

It may be even worse than that. Maybe there's some other complicated factor that interacts with the SNPs I see from 23andme. Like, say, the types of bacteria in my stomach maybe account for the obesity (or lack of it). The whole thing might just be too complicated to figure out.