Credit: Deutsches Bundesarchiv (German Federal Archive)
A storm of protest broke out a month or so ago when a fertility clinic in Los Angeles announced it would start helping women choose what their babies might look like. The ruckus was loud enough that the clinic has since backed off on this service.

And this is probably a good thing. I am not sure this is a road we want to go down– it smacks a bit too much of Hitler and a perfect race.

Of course, we’ve started down this road a ways already. We aren’t able to shape anyone’s DNA yet. We don’t have the technology to do this in any safe or reliable way and frankly, it’ll probably be a long time before we can.

But we can take a peek at an embryo’s DNA if the egg has been fertilized outside of the body. The process is called preimplantation genetic diagnosis or PGD. Using PGD, scientists can look through a number of embryos’ DNA and pick the one(s) the parents want.

Right now we can’t scan all of an embryo’s DNA. We have to pick and choose what part of the DNA to look at.

For example, PGD is often used to make sure that an embryo has all 46 chromosomes. This service increases the chances for a successful birth for women who are going through repeated miscarriages.

Of course, if we can look at the chromosomes, we can also tell whether the embryo is a boy or a girl. Often this is done to select for girls in families that carry male specific genetic diseases like Duchenne muscular dystrophy. But it is also done for the less life threatening goal of an even number of boys and girls in a family (gender balancing).

PGD can also be used to make sure an embryo did not inherit specific diseases like cystic fibrosis or sickle cell anemia that might run in the parents’ families. These diseases can be screened for by looking for specific DNA differences in certain genes. Which is what this fertility clinic wanted to do for hair, skin and eye color genes.

Let’s say a parent wants a redhead with brown eyes. The clinic would screen for certain versions of the HERC2 gene that mean brown eyes and certain versions of the MC1R gene that indicate red hair. When they found an embryo with the right combination of traits, then that embryo would be selected for implantation.

Remember, the people at the clinic can’t change the DNA of the embryo. They can only sort through the genes that are already in the pool. So if one parent doesn’t carry a red hair version of MC1R, then the parents can’t have a red haired child.

Even without this ability, the furor over the fertility clinic’s service raises a very important discussion point– where do we draw the line with PGD? And who should draw that line?

Obviously eye color is going too far (or is it?) and preventing an early death from a genetic disease is OK. But is it OK to look at gender for family balancing? This is allowed in the U.S. right now but is not permitted in most other countries.

What about conditions like high cholesterol? Or diseases that kill later in life like Huntington’s disease? Or traits like height, weight, or intelligence? Who gets to decide?

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Designer Babies 30 March,2009Dr. Barry Starr

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  • Anon

    I’m just curious – what if a Scandinavian man with blue eyes has an Asian wife who has brown or dark eyes, and the couple wants their baby to have blue eyes? Is it possible for them to have a blue eyed baby? I am wondering because I was just reading about Mendell’s laws, and was under the impression that the genes that result in more melanin production (and also darker hair and eye color) were dominant. Doesn’t that mean it would be impossible for the couple to have a baby with blue eyes?

    Edit: I mean to say, doesn’t it mean its impossible for them to have a baby with blue eyes even if this technique is applied?

    • Brittany

      I think the the odds for that are very very low but I think if they were to sort through enough embryos they would eventually find one with them traits but it would take a while. Like where the dominant gene for some reason wasn’t dominant in this case, like dark skinned people with light eyes
      Did that make sense?
      It’s very rare but possible

  • Anon

    Why is this preimplantation genetic diagnosis not acceptable but the morning after pill is? They both result in dead embryos, so what’s the difference?


Dr. Barry Starr

Dr. Barry Starr (@geneticsboy) is a Geneticist-in-Residence at The Tech Museum of Innovation in San Jose, CA and runs their Stanford at The Tech program. The program is part of an ongoing collaboration between the Stanford Department of Genetics and The Tech Museum of Innovation. Together these two partners created the Genetics: Technology with a Twist exhibition.

You can also see additional posts by Barry at KQED Science, and read his previous contributions to QUEST, a project dedicated to exploring the Science of Sustainability.

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