Genetic tests often don’t give as much information as you might think.In a previous blog I talked about getting my DNA tested with 23andMe.  Well, I got the email the other day saying that my results were ready.  So I logged on and up popped this screen pictured to the left.

All sorts of goodies to try out!  I feel like a kid at Christmas.

The first thing I thought I’d do is check out my ancestry.  My grandfather’s grandmother was supposedly Native American and so I wanted to find out if I could see that in my DNA.  (This relates to my supposed relationship with the outlaw Sam Starr but that is a different story.)

23andMe has this Native American testing app in their 23andMe Labs section.  I clicked on my data and up popped this result:

Recent Native American ancestry is unlikely

Has it all been lies?  My great, great grandma wasn’t Native American?  Not so fast…

A “no” answer on a genetics test doesn’t necessarily tell you a lot.  (And sometimes, the “yes” answer isn’t so helpful either!)   Now as a geneticist, I know the drawbacks of ancestry tests like these.  What I wanted to see was if 23andMe did a good job of explaining them.

I first checked out my mitochondrial DNA (mtDNA) and my Y chromosome data.  These DNA don’t change a lot from generation to generation and so are really good at tracing ancestry many generations back.  Their downside for me is how they are passed down.

The Y chromosome passes from father to sons.  My great, great grandma didn’t have a Y to pass on so of course my Y chromosome data wouldn’t show that she was Native American.

mtDNA passes from mom to her children.  At first this sounds promising since we are talking about my great, great grandma until we realize that I am related to this woman through my grandfather.  His mtDNA died with him (except for his female relatives and their descendants) so that is lost to me as well.

Here is what 23andMe has written under interpretation of my mtDNA and Y chromosome results:

This mitochondrial DNA haplogroup is inconsistent with Native American ancestry along the maternal (mother's mother's mother's …) line.

This Y chromosome haplogroup is inconsistent with Native American ancestry along the paternal (father's father's father's …) line.

I suppose this says what I just said but I am not sure how many people would really appreciate the limitations of mtDNA and Y chromosome data from this explanation.  There wasn’t a link to a more explicit discussion of the limitations of this sort of testing and there wasn’t anything I could see from a quick glance at the ancestry part of the site either.  An explicit explanation would be good or maybe a figure like this one:

To me, this drives home the point that there is a whole lot of missing ancestry.  It might help if they had some sort of family tree app where you could indicate as much as you know about family relationships.  Once you’ve inputted the data, it would spit out what tests results would be useful to look at.

So the mtDNA and Y chromosome test results are of little use to me in this quest.  (And of little use to me in general as it confirms my pasty whiteness.)  Next blog I’ll deal with the rest of my DNA and what that can and can’t tell me about my great, great grandma.

Artificial Turf. Credit: Anthony V. ThompsonIt's easy to get scared. You look around the Oakland office of the Center for Environmental Health, and lead is everywhere. Piles of toys that are loaded with lead. Lunch boxes and kids' backpacks that have tested positive for high levels of lead. Samples of artificial turf.

And that's just the beginning. Lead has been found in venetian blinds, in pens, in the glaze of ceramic cups and bowls. It has been found in imported candies. And one Mexican folk remedy to cure stomachaches has landed a number of children in the hospital recently – a packet of powder that is almost entirely lead.

Since the effects of lead are cumulative, all those points of contamination add up.

Children's developing brains and central nervous systems are most susceptible to damage from ingesting lead. That's why a new federal standard for lead in children's products was recently put in place. And that's why the Center for Environmental Health, for one, focuses on products that come in contact with children on a daily basis.

The amount of lead in artificial turf, by itself, is unlikely to cause lead poisoning. And the same is true for the amount of lead found in lunch boxes, or in children's jewelry. But medical experts say that if kids play on artificial turf in the morning, distractedly put a charm bracelet in their mouths during class, and eat food from a lunch box with lead embedded in the vinyl – then those kids are at risk for lead impairment, such as a loss of IQ points, a sign of brain damage. For more, listen to the QUEST Radio story, or check our photos below.