Pre-implantation Genetic Diagnosis (PGD) is a procedure wherein one cell of an eight-celled embryo is removed and eugenically tested for defects, sex, appearance attributes–whatever the prospective parents wish to cull from their prospective families by discarding embryos that don’t measure up. But a new study casts doubt that the procedure is safe for the baby that is allowed to be born. From the story:
Ran Huo, Qi Zhou and colleagues used a mouse model to examine how a blastomere biopsy, as the key manipulation during the PGD procedure, could affect fetal, neonatal and adult development. They found that there were no differences in embryo development prior to uterine implantation in the biopsied and control groups, which is consistent with results found in humans. However, following implantation, successful births from biopsied embryos were significantly lower than in controls.
Following birth, the authors tracked many physical and behavioral properties; the two groups of mice were similar in many respects, though mice in the biopsied group on average had higher body weight and poorer memory in maze tests. To get a more detailed picture of these memory defects, the authors performed a proteomic analysis of adult mouse brains; 36 proteins displayed significant differences between biopsied and control groups, 17 of which are closely associated with neurodegenerative disorders like Alzheimers and Down Syndrome. The authors suggest that the developing nervous system may be sensitive to blastomere biopsy, and that more studies should be performed to address any possible long-term adverse effects of PGD to ensure its safety.
Shouldn’t that have been done before PGD became routine?
The whole field of IVF has been practiced recklessly from the start, with little safety testing, and in the USA, virtually no regulations. Alas, that is unlikely to change. Bioethicists and reproductive health lawyers dogmatically assert that people have both a right to procreate by whatever means they choose, and have the right to produce the kind of baby they want, which requires PDG. In such an anything goes milieu, the words “slow down” simply do not resonate.
July 21st, 2009 | 2:43 pm
[...] embryo for eugenic testing, might not be safe for the babies who are allowed to be born. More details available over at Secondhand Smoke. Comments [...]
July 21st, 2009 | 3:02 pm
Wesley: You sound as if you’re saying this is already a procedure being carried out on human embryos, when the article is saying it’s being done carried out on mice. Artificial uterine implantation has similar successful results in both mice and humans, but the biopsy process in mice has resulted in complications between the experimental group and the control group. Nowhere in the article does it say that human PGD has ever been “routine.” Where did you get the idea that it was?
July 21st, 2009 | 3:46 pm
History Writer: Of course it is already being carried out on humans. Has been for years. How do you think they select embryos to not have certain genetic diseases, even a propensity to adult onset cancer and hair color? Have you not read my many posts on this matter? In any event, they forged ahead without these kind of animal studies, apparently.
July 21st, 2009 | 5:06 pm
Of course it is routine. It was suggested to me by a facial surgeon years ago in case I wanted to “weed out” future children who might have my minor genetic anomaly, Saethre-Chotzen Syndrome.
July 21st, 2009 | 6:38 pm
Duh. The process damages the embryo to begin with. What’s one-eighth of an adult mouse (or human) body — an arm, a leg, what, you expect no consequences to chopping it off during its most intense developmental activity? Duh.
July 21st, 2009 | 7:01 pm
What’s also suprising to me is how confident and assuring people who play with these embryos have been in saying that embryologists, or whoever does this, routinely pluck a cell at the eight cell stage and that it doesn’t do any harm. They say it so confidently as if everyone knows and that it’s settled science. I think this confidence was most on display with Robert Lanza and his claim that he and ACT had developed some sort of embryonic stem cell line by plucking single embryo cells from multiple embryos without harming them in August 2006. It didn’t work, but their stock went up 400 percent over night. I think Lanza had spoken about how routinely this is done without harming embryos. I remember being at a lecture by Fr. Tad Pacholcyzk a couple of years ago when he said we didn’t know that this didn’t injure people later. That was the first I heard that this could pose some injury or danger to humans later in life.
July 21st, 2009 | 7:23 pm
Interesting increase in weight and loss of memory. Is that what happened to America?
July 22nd, 2009 | 1:31 pm
Am I mistaken? I thought most if not all “genetic predisposition” conclusions were arrived at by amniocentesis, not via biopsy at the 8-cell stage. Why would anyone want to perform a biopsy at that stage when you can get all the cellular material you need a month later from amniotic fluid? Are there that many people who interested in frivolous things like hair- and eye-color that they’d risk a doctor’s performing what is in effect a procedure-in-development? It makes no sense at all.
July 22nd, 2009 | 2:15 pm
IVF, HistoryWriter. Hence the “Pre-implantation” part of the procedure’s name. The biopsy is done to see if the IVF-produced embryo has or lacks certain genetic characteristics before deciding to implant the embryo in the mother.
And as to deciding whether to implant based on hair color, etc., a lot of IVF embryos are created from donor eggs. Many times prospective parents will look for egg donors with “desireable” genetic characteristics like athletic ability, high test scores, etc. Some of the ads read like recruitment posters for the Waffen SS and the whole thing gives me the creeps. But I would not be surprised to find that PGD for cosmetic factors such as eyes and hair are common in IVF.
July 22nd, 2009 | 2:27 pm
History Writer, the reason is because the woman doesn’t want to go through the physical state of pregnancy with a child she does not want. If a number of embryos have been conceived by IVF, it is of course far lower cost both in literal terms and in emotional-physical terms for the mother to test them at the 8-cell stage _before_ implantation and bio-incinerate the unwanted embryos than for the mother to go through part of a pregnancy and then terminate the unwanted children by abortion later.
I, of course, consider all of this abominable. But I’m trying to explain to you why people do it, since you’ve apparently been previously unfamiliar with this fairly common concomitant to IVF. Even when it is not done for eye color, it is done for plenty of other genetic reasons–as in the example I gave and many others. You might or might not consider them frivolous, given your other opinions, but the point of the main post is that people have believed for a long time that there is zero cost to the _wanted_ children, the embryos who are found _not_ to have the unwanted genetic characteristic, and this research casts doubt on that assumption.
July 22nd, 2009 | 8:47 pm
Wow! THAT was an education!
July 24th, 2009 | 1:11 am
Wow, I guess I have to hope that this is not true, on behalf of the people who this was done to, so that they turn out to be “normal”. But then again, there are lots of people overweight with damaged brains, so maybe it’s better just to hope for all people’s happiness and fullness of spirit, in spite of them not being perfect, that way I can hope it is true. Then maybe “procreative beneficence” would lead to skipping PGD instead of feeling pressured into it.
Man, it’s hard to believe we let them get away with pressuring people into doing this, instead of stopping it.
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