
By Elianna Miller
In late 2018, “CRISPR babies” made news worldwide, and they
are now coming back to the spotlight. When He Jiankui made genetically modified
embryos that grew into twin girls with HIV immunity, people were outraged. He
didn’t discuss his plans with his scientific community, and the procedure was deemed
unnecessary and risky. These so called “CRISPR babies” were viewed with great
controversy and caused
a halt in the global scientific community on gene-edited embryos.
Now, Russian scientist Denis Rebrikov has announced his desire to
produce CRISPR babies
that can hear from parents with recessive genetic deafness. Because both
parents have an altered copy of a gene related to hearing, any child they naturally
conceive would be deaf, too. The participants want to provide their children
with the ability to hear. Rebrikov plans to consult scientific communities and
explain the benefits of the process, unlike He.
So,
what is CRISPR?
It’s a groundbreaking technology that is often seen in the news but less often
well understood. Short for Clustered Regularly Interspaced
Short Palindromic Regions, multiple repeats of the same 30
or so base pairs are separated by different genes of interest (spacers). Spacers
serve as a guide for an enzyme, usually Cas9, to cut specific pieces of the
genetic code. When this “faulty” DNA is cut, that gene is essentially turned
off.
The cutting also acts as marking, and other molecular
components can guide new DNA to that marked spot. This unfortunately doesn’t always
work perfectly. Since there are so many repeats, the cutting enzyme can go to
the wrong spot, editing unintentionally. Rebrikov still wants to use this process
to insert “hearing genes” into embryos regardless of the imperfect mechanism.
Many ethical dilemmas arise here. There is no consensus on
who gets to decide when CRISPR should or should not be used. Right now, the
ability to hear is a product of environment and parental genes, and scientists
like Rebrikov are attempting to change those factors with this new technology.
The
Center for Genetics and Society talks
about CRISPR in the context of disability rights, and the range of perspectives
needed when making decisions about cutting genes from embryos. They note that removing
genes linked to certain characteristics is marking them as tragic, implying impossibility
of a good life. How can we respect people living with certain conditions that
we are choosing to eliminate from others? Also, where do boundaries lie, and
how do we draw the line on what genes can be edited? If we can edit out certain
genetic disorders, what will stop us from selecting for certain eye colors, heights,
or intelligence capacities? These are difficult questions that will be debated again
and again as CRISPR gene editing technology advances and begins to touch more
lives.
To learn more about CRISPR along with the research and
ethics of it, sign up for the Norton and Elaine Sarnoff Center for Jewish Genetics’
event: CRISPR:
Is Gene Editing Kosher? We
will be discussing potential answers and the lack thereof for questions like
these.
References:
https://www.sciencedirect.com/science/article/pii/S216225311630049X
https://www.flickr.com/photos/genomegov/39603195652/