Sunday, March 10, 2013

23XandMe: Direct-to-consumer (DTC) genetic testing

I knew about 23XandMe a few days ago, since then I have been looking for information, wondering if it is a good investment. And I have not researched enough and possibly I do not understand half of what I've read, but I would like to share what I've seen.

This company (23XandMe), based in California, has already six years selling personalized genome tests. And last year this companyreceived extra money , which allowed a large cost reduction, from 300 to ~100 dls per test. But what exactly 23xandMe does?

Well, if you agree terms and conditions (exactly, those we never read), register and pay 99 dls, you will receive a box the very next day, like the one in the picture above, with a test-tube in which you have to spit 2.5 ml. Then you have to return your sample to the company (everything is included in the 99 dls). These people will perform a chip test of your DNA (Illumina OmniExpress Plus Genotyping BeadChip), analyzing your genome for 960 000 SNPs (it is estimated that in the human population there are about 10 million SNPs). Later (like two or three weeks later) in the webpage you will be able to see if these SNPs you have make you a person with high risk for diabetes or cancer. Also, the webpage will display your overall probable global origin and your Neanderthal percentage, maternal and parental lineages. There are around 200 traits you will know, but some require additional payments (most of them, actually). If you’d like to know more about the details of this kit, how it looks like, please visit this link .

At first it seemed to me something interesting, I thought it would be an opportunity to learn more about the other 50% of my genetic background, because in my case I do not know anything about that 50%, only the last name, but that has never been of much help. And in fact, I found somepeople that are adopt and bought the kit just for that very reason, to learn more.

But then I read that 23XandMe only analyze a few markersthat account for cancer. Besides, the comparison to determine if you are on average more prone to one illness or another is based on the database of the same company, which include something close to 200,000 people from a few countries (yes yes, we are in total over 7 billion, and counting).

In the webpage this product is announced under the slogan "knowledge is power" ... but I wonder, what power? power to whom?? If my results will be displayed as the sample below, what do exactly does that my DNA may be related to someone like Thomas Jefferson (whoooot?? Yeap, check the picture), what will be different if I know that the composition of my ancestry is mostly from Africa, or America ...

At least, for me at this moment, this is not much. And it is true, we do not need to sequence our genome to know that we have to eat healthy, do more exercise and sleep well in order to reduce illness risk (@moorejh, 2013).  I think, to some extent we have not understood how we work, how we interact with the environment, how our own genes interact, and that’s why predict is very risky, isn't it?
Or maybe it is not, because the technology 23XandMe is using is very (very) accurate. Although as I told you before, measuring and predicting the risk for breast cancer based on two markers that are known account for only 5% of the total incidence, does not give a sense of confidence.

But this does not stop here. The goal of 23XandMe is to increment its database from 200 000 to one million people, obviously, as long as these people allow their data to be used for research. Because that is something else, when you complete your registration you will be asked to accept your data to be used for research (although the webpage says the founders do not seek to publish any paper), apparently in the future the genetic material of a million humans could be used by other research centers to develop serious breakthroughs.

And recently, I saw that if right now, you find any variant that was not tested by 23XandMe, there is an algorithm (the imputationalgorithm), which enables you to calculate the possibility of such variant is in your genome, through a comparison with other databases, such as 1000 Genomes and HapMap. Isn't it amazing?

Now 23XandMe it is not the only DTC company, but as far as I know 23XandMe is the cheapest one, some others like deCODEme charge around 1000 dls (although for some reason deCODEme is not selling directly to consumer), I’d like to know if they test the same markers as 23XandMe.

For now I do not know what to conclude, on the one hand I find fascinating all this and I really want to see what will happen with these technologies, what’s next with the DTC companies. But on the other, I’m not convinced to be part of the million of genomes, first because I'm not rich and I can’t afford to spend 100 dls just out of curiosity, second because I know what I need to improve if I don’t want to get sick, and third, because knowing my paternal lineage will not change anything. Let’s see what happens this year with 23XandMe, let’s see if they manage to get one million genomes.

If you want to know more about 23XandMe, you can check the Wikipediaarticle, although it is not really good, it has useful references.

Saturday, March 9, 2013


Recommending a good website for those who are interested in astronomy or skywatching, or those who just like to see this kind of animations of the universe, just to realize how little we are.