Getting to Know Your DNA

Image source: Chris 73If you could know more about your DNA, would you want to? And if you want to know more, is now the time to find out?

You might think so given the flurry of company launches in the last few days. These companies promise to help "decode" your genetics (deCODEme). Or reveal vital information about your 23 chromosomes (23andMe). Or help you navigate your personal genomics (Navigenics).

What makes these companies different from older genetic testing companies is that they look at lots of DNA all at once instead of just a single gene. (They aren't looking at all of your DNA-- for that you need to contact Knome who will do this for a mere $349,000.) This means they can look at many different genes and DNA markers at once giving a broader view of the genetic you.

For around $1000, these companies will take this deep look at your DNA and tell you a bit about your ancestry. They will also be able to tell you a bit about your risk for some diseases. And maybe tell you how likely you are to have a child with blue eyes or red hair. They might even find a genetic reason why you hate Brussels sprouts (take that mom!).

Given how little we know right now about our DNA, I am not sure if these results are worth $1000. A little bit of knowledge can be a dangerous thing. And scientists don't know much yet about our DNA.

You'd think they'd know more given that they sequenced the human genome back in 2003. But just because we have the six billion letters, it doesn't mean we know what they do. Or how different bits influence each other.

Our DNA right now is a little like Egyptian hieroglyphics were before the Rosetta stone was found. We know a bit about our DNA but not a whole lot. Scientists probably won't find a magic stone that unlocks the secrets of our DNA in one fell swoop. Instead they'll need to painstakingly create their own Rosetta stone. This will take time and we are not very far along yet.

Unfortunately since we won't find a magic decoder ring, we will find things out in fits and starts. And results will change over time. This means that there may be times when the incompleteness of our information means we have the wrong information.

One study might tell you that a certain version of gene X increases your risk for breast cancer. Later you find that you have a certain version of gene Y that cancels out that risk. So you were very worried before when you didn't need to be. And who knows if they’ll find gene Z that cancels out gene Y and puts you at risk again!

Possible results like these suggest to me that some of the older companies that look at single genes may be the best bet for now. It sounds stodgy, but if a strongly genetic disease runs in your family, then a genetic test that looks at a single gene may be right for you. Unless you want to do your bit for these new companies (and science).

These companies will learn from your DNA-- in essence you'll be funding their research. As they learn more, they'll be able to offer their customers (and hopefully science) more information. You'll need to decide if that combined with the broad but shallow information they offer is right for you.

Dr. Barry Starr is a Geneticist-in-Residence at The Tech Museum of Innovation in San Jose, CA.

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