Carl Zimmer

Like we know that's caused by one mutation at one gene.

And if your mother or father had Huntington's disease, you have a 50% chance of inheriting that one mutation.

If you did...

You're going to get Huntington's disease.

And so if you go on and develop Huntington's disease, people can say like, well, it's a shame that he got it from his mother.

And we know that.

That's clear cut.

But those diseases are rare.

So just say like, oh, he drinks because his father drank.

Yeah, I think that's too glib.

I am, as you can tell by writing a book about this sort of stuff, I am intensely fascinated by how our genes influence us.

But when people get these results from these companies...

I think they're looking for quick and simple answers.

Tell me what my DNA says about me.

That's a complicated thing to tell for the most part.

It's pretty easy to say, hey, you have this mutation that if you're a man means you're colorblind.

That's pretty clear.

But when you start to get into issues about, say, risks of diseases,

then you really need to read that fine print.

23andMe is now starting to provide results for your risks of diseases like breast cancer and other diseases.