Genome editing is a group of technologies that serve to help scientists alter an organism’s DNA. The technologies allow for genetic material to be added, removed, or relocated at particular locations in the genome.
Although there are several approaches to genome editing, a more recent one called CRISPR-Cas9 has generated excitement within the scientific community because of its simplicity, inexpensiveness, and availability of use.
CRISPR-Cas9 is short for clustered regularly interspaced short palindromic repeats and CRISPR-associated protein 9.
“CRISPR palindromic repeats play an important role in microbial immunity. When a virus infects a microbial cell, the microbe employs a special CRISPR-associated nuclease (Cas9) to chop off a piece of the viral DNA,” according to synthego.com. “The snipped DNA fragment may then be stored between the palindromic CRISPR sequences to retain a genetic memory for disabling future infections from the same viral strains.”
This revolutionary breakthrough was made when scientists finally learned how the CRISPR system worked in bacteria and figured out how to reprogram it to allow it to be used to edit in any species.
The tool relies on three components: the molecular scissors, a CRISPR-associated (Cas) nuclease, and the GPS guiding it to the appropriate site, the guide RNA (gRNA). It differs from previous genetic engineering techniques because it allows for the introduction or removal of more than one gene at a time. This makes it possible to manipulate many different genes in a cell line very quickly, reducing the process from taking a number of years to just a few weeks.
From its original discovery in 1987 by a Japanese team of scientists at Osaka University, it took around two decades before Eugene Koonin and his colleagues at the National Center for Biotechnology Information demonstrated for the first time how the CRISPR-Cas 9 mechanism worked in 2008, according to whatisbiotechnology.org.
Although CRISPR has primarily been used for treating diseases and has also had a huge impact on agriculture and editing plant genomes, CRISPR technology has also shown to have potential in other areas, such as developing disease models and biofuels. And, in January of 2013, a number of researchers at different laboratories published papers within a few weeks of each other that demonstrated how the system could be used to edit genomes in human cells.
Using human embryos sourced from a fertility clinic, Chinese scientists tried to use CRISPR-Cas9 to edit a gene that causes beta-thalassemia (a blood disorder that reduces the production of hemoglobin) in every cell. Although the donor embryos used would not have resulted in a live birth, the experiment ended poorly. Out of 86 embryos injected, only 28 were successfully spliced, and very few contained the genetic material the researchers intended to find. In addition, it’s very likely more damage was done that went undocumented.
“The Chinese researchers point out that in their experiment gene editing almost certainly caused more extensive damage than they documented; they did not examine the entire genomes of the embryo cells,” Gina Kolata from the New York Times explained.
Between the failed experiment and the general issue of ethics, this discovery produced controversy within the scientific community.
In November 2016, another group of Chinese scientists became the first to use CRISPR-Cas9 on an adult human. The scientists injected a lung cancer sufferer with the patient’s modified immune cells by CRISPR to theoretically help the patient’s body fight back against cancer. The effort was successful.
Later, in a study published in August 2018, scientists successfully ‘edited’ human embryos, removing the portion of DNA that can lead to hereditary heart disease.
While it is one thing to be able to remove the DNA that could lead to life-threatening diseases, there are genuine ethical concerns at play here.
First, this is still a relatively new engineering technique, one that does not guarantee success every time. Even if the process of tampering with the embryos worked flawlessly, there is no telling what side-effects might occur later on during a person’s life.
Even though no one can argue the benefits of being able to prevent viruses and diseases from within a human embryo, this is a double-edged sword.
For example, if a scientist can identify the gene that causes breast cancer, they could potentially change anything about a person. That means scientists could literally make superhumans. They’d be able to program their children to be smarter, faster, or have preferred features.
This is essentially forcing evolution.
Even if people accept this as something we have the potential to do, it does not change the fact that it isn’t something we should. CRISPR-Cas9 will likely become heavily commercialized, meaning the procedure itself would be cheap, but only the wealthy would be able to afford the hefty price it would cost to genetically modify their offspring, thus increasing the disparity between the wealthy and the middle and lower classes.
We have already seen other methods used to determine things such as gender. A perfect example is Chrissy Teigan and John Legend choosing the gender of their child (a girl) through in vitro or IVF. The method was originally used to screen for genetic disorders, but a result of modern IVF is learning the gender of the embryos.
According to Jeffrey Steinberg, M.D., a leading IVF specialist, there are a growing number of couples—some 70 percent of the patients in Steinberg’s practice—who use IVF specifically so that they can choose a son or a daughter.
If we are already seeing a trend in the specific selection of gender by couples, it is highly likely that the same thing would be in store for CRISPR.
This is going too far.
As fascinating as this opportunity seems, it doesn’t mean it should be seized. It’s better to listen to the group of American scientists who have told us to stay away from manipulating these kinds of things and simply leave our future generations be-at least in terms of personal preference.