CRISPR and the Ethics of Genome Editing

Joel Eissenberg, Professor of Biochemistry and Molecular Biology and Associate Dean for Research at Saint Louis University School of Medicine. 

In Our Image: The Ethics of CRISPR Genome Editing , Joel C. Eissenberg, De Gruyter | 2021

Humanity has been busily modifying plant and animal genomes for centuries. It has long been a dream to speed up and target that process. Additionally, the promise of molecular cloning included the hope of curing genetic disease once the gene is identified. These aspirations are being met, incrementally. Now, the CRISPR technology for genome editing promises to deliver on those hopes. The economic impact of genome editing in crops and livestock will be felt in short order. In the sphere of human health, there is both the prospect of editing the human genome to correct inherited disorders, as well as extinguishing plagues that have devastated human populations for millennia. There are a number of clinical trials underway to exploit CRSPR technology to treat inherited disease. The genetic tools to drive pest species (insects, weeds) to extinction are being developed and tested.

We can now do all these things, but should we?

The ethics of genome editing limited to the somatic cells (all cells except sperm and egg and the cells that can give rise to them) are no more complicated than the ethics of drugs or vaccines. The consequences of editing in these cases are limited to the treated individual and die when the person dies. Where genome editing becomes ethically fraught is when the products can enter the human gene pool through reproduction. That horse left the barn a couple years back when Dr. Jiankui He infamously announced the birth of twins that he had engineered as embryos to be resistant to HIV. There is no assurance that either of these twins don’t carry off-target mutations as a result of the editing mechanism. Further, the CCR5 gene mutation that was engineered in the twins may affect their susceptibility to other diseases. Since they carry the edited chromosome(s) in their germ lines, they can pass these edits to future generations.

But what if a couple is a risk for conceiving a child that carries a terrible inherited disease like Tay-Sachs or Huntingtons? There are alternatives available to couples who want children and who carry mutations that cause inherited disease. Couples can choose:

• embryo selection to implant an embryo that doesn’t carry the disease allele,

• a sperm or egg donor which doesn’t carry the disease allele, or

• an adoption.

From these choices, it is clear that germline genome editing isn’t “therapy,” since there isn’t a person being treated. Thus, the ethical claims for germline therapy don’t weigh against humanity’s concern about introducing new genetic risk in the human gene pool.

Turning now to the topic of CRISPR editing to eradicate pest species. While we can all agree that eliminating the pandemic scourges such as plague, malaria, yellow fever and dengue would be ethical, the approach of driving the disease vectors to extinction raises ethical issues beyond the prevention of disease. Same with eliminating weed species to increase crop yields. Ultimately, genetically modified organisms don’t observe international boundaries, so release of so-called “gene drives” capable of driving a pest species to extinction can’t be contained within the boundaries of the state that originates them. The ethics of deciding which animals and plants should be eradicated and who gets to decide has not kept up with the technology to do so, and isn’t as well-funded as the companies pursuing these goals.

Why talk about this on an econ blog? Because there’s lots of money to be made, with the prospect of transforming the world in our own image.  More details on CRISPR, its applications and the ethics at the link:

In Our Image: The Ethics of CRISPR Genome Editing , De Gruyter | 2021