From: Hal Finney (hal@finney.org)
Date: Thu May 02 2002 - 17:41:22 MDT
Greg Stock made another interesting point at the talk I attended two
weeks ago, regarding the possible impact of embryo screening technology
in the relatively near term.
Embryo screening is practiced already by people at high risk of having
children with certain birth defects. An embryo is created with IVF
and then grown to about the 6 cell stage. At that point a cell can be
removed without any long-term harm to the embryo, and a genetic analysis
is performed to identify any problems. In this way only healthy embryos
are implanted to grow into babies.
With fertility drugs, women can produce half a dozen or more eggs
at a time, creating that many embryos. In that case there would be
more embryos to choose from and theoretically it would be possible to
do a more intensive genetic screening for selecting desirable traits.
The most obvious is sex selection, but as we learn more about genetics
it will be possible to do much more.
There has already been some work on trying to identify certain genes
which are more common in high IQ people. Robert Plomin of the London
Institute of Psychiatry identified the first "IQ gene", which codes for
a protein involved in glucose metabolism. High IQ children were twice
as likely as controls to have a particular flavor of the gene.
http://www.mugu.com/upstream-list-archive/1996-1998/msg00466.html,
ongoing research is briefly described at
http://www.uwcm.ac.uk/study/medicine/psychological_medicine/neuropsychiatric_genetics/research/iq.htm.
So it is likely that in a few years we would be able to screen an embryo
for how well it correlates with the various known high IQ genes. This
would allow us to predict to some extent the future IQ of that embryo.
Current techniques give only a handful of embryos to work with per parent.
Women are born with their entire complement of several hundred eggs
which will normally be "ripened" and released once per month during their
fertile years. Large numbers of eggs can be removed with a relatively
simple surgicle procedure, but so far it is not known how to "ripen"
them and make them ready to be fertilized.
Stock predicted that in a few years it might be learned how to do this.
This would then allow a couple to have IVF done on potentially as many as
100 embryos at a time. These could then be screened using the knowledge
we will have in a few years about IQ genes, and the embryo with the
highest potential could be selected for implanting.
The amazing thing about all this is that, according to Stock, if a
couple with an average IQ of 100 were to do this to 100 embryos, then
the average IQ of the child would be increased to 120. That's about
1.3 standard deviations which would be equivalent to raising the SAT
combined score by 260 points (an oversimplification because college
applicants already have higher than average IQ scores).
This would clearly be a much safer technique than unproven genetic
engineering to try to insert "good" genes into the embryo. It does not
require technology much beyond what we already have, and work is already
under way to identify IQ genes, so that information will probably be
available in a few years.
There has been quite a bit of controversy and discussion already about
embryo screening. Doing a google search on that phrase, or on the
technical name, pre-implantation genetic diagnosis (PGD) will find
many interesting articles. PGD is already adding tremendous value to
people's lives by freeing them of the awful fear of passing on horrible
genetic diseases to their children. It is probably just a matter of
time before it begins to be used for enhancement as well; not just IQ,
but other traits such as longevity and fitness will have many gene
correlates known before long.
That "bioluddite" group we were talking about the other day,
www.genetics-and-society.org, specifically objected to embryo screening
for anything other than eliminating birth defects and similarly harmful
genetic patterns. They didn't even like sex selection. So choosing
the theoretically "smartest" embryos would definitely be something they
would oppose.
I think this would be a better battleground or us than fighting for
reproductive cloning. Embryo screening will allow us to give our children
a tremendous gift, a stronger and healthier genome which will benefit
them their entire lives. It's controversial, but according to Stock a
substantial number of people favor genetic enhancement, something like 50%
in the U.S. As the statistics above show, the potential advantages to
the child are huge. I'll bet in 20 years it will be either outlawed or
routinely used in Western countries. It's the Gattaca world coming true.
Hal
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