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by Stephen Johnson
22 February,
2019
from
BigThink Website
Chinese scientist He Jiankui
The
brains of
two genetically
edited babies
born last year
in China might have
enhanced memory
and cognition,
but that doesn't
mean
the scientific
community is pleased.
-
In November, Chinese scientist He Jiankui reported
that he'd used the CRISPR tool to edit the embryos
of two girls.
-
He deleted a gene called CCR5, which allows humans
to contract HIV, the virus which causes AIDS.
-
In addition to blocking AIDS, deleting this gene
might also have positive effects on memory and
cognition. Still, virtually all scientists say we're
not ready to use gene-editing technology on babies.
The controversial decision to genetically edit the embryos of two
girls born in China last year might have enhanced their memory and
cognition, scientists say.
Chinese scientist He Jiankui reported in November that he'd
used the
CRISPR editing tool to delete a
gene called
CCR5, which enables humans to
contract HIV, the virus that causes
AIDS.
In addition to
potentially blocking the development of AIDS, recent research (CCR5
is a Therapeutic Target for Recovery after Stroke and Traumatic
Brain Injury) suggests knocking out CCR5 can also make
mice smarter and help the human brain recover from strokes.
"The answer is likely
yes, it did affect their brains," Alcino J. Silva, a
neurobiologist at the University of California, Los Angeles,
whose lab studied the CCR5 gene's role in memory and cognition,
told MIT Technology Review.
"The simplest
interpretation is that those mutations will probably have an
impact on cognitive function in the twins."
Despite any potential
benefits, the scientific community has almost universally condemned
the move, which was generally described as a premature use of
technology whose physiological and philosophical consequences on
human life remain unclear.
When Alcino J. Silva
learned he had used CRISPR to delete the CCR5 gene, his reaction
was,
"visceral repulsion
and sadness."
"I suddenly realized,
'Oh, holy shit, they are really serious about this bullshit',"
he told MIT Technology Review.
The CRISPR
co-founder's response to He
Jennifer Doudna, a professor of chemistry and molecular and
cell biology at UC Berkeley and co-inventor of CRISPR,
published a statement in November
saying the public should consider the following points on the use of
gene-editing technology:
-
The clinical
report has not been published in the peer-reviewed
scientific literature.
-
Because the data
has not been peer reviewed, the fidelity of the gene editing
process cannot be evaluated.
-
The work, as
described to date, reinforces the urgent need to confine the
use of gene editing in human embryos to cases where a clear
unmet medical need exists, and where no other medical
approach is a viable option, as recommended by the National
Academy of Sciences.
In 2017, Doudna spoke to
us about the tricky regulatory and philosophical questions we might
soon wrestle with if
genetically designing babies
becomes an option for parents.
As Silva told MIT Technology Review, this kind of selective
gene-editing wouldn't just have consequences for parents and their
kids, but also for society at large:
"Could it be
conceivable that at one point in the future we could increase
the average IQ of the population?
I would not be a
scientist if I said no. The work in mice demonstrates the answer
may be yes. But mice are not people. We simply don't know what
the consequences will be in mucking around.
We are not ready for
it yet."
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