AT A SCIENTIFIC conference held in June, researchers from two U.S.-based biotech companies announced they had treated 44 patients suffering from beta thalassemia — a blood disorder, found primarily in Southeast Asia and Africa, that negatively impacts the production of hemoglobin and can lead to a shortened lifespan. In its most severe forms, frequent blood transfusions are needed. After the experimental treatment, 42 of those patients no longer needed any blood transfusions. Additionally, the companies reported treating 31 patients with sickle cell disease, which disproportionately impacts populations in sub-Saharan Africa, as well as approximately 100,000 Americans. After treatment, none of these patients continued to have the recurrent painful symptoms that often lead to hospitalization.
All these patients were treated with an innovative approach that depended on the gene-editing technology CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats). In the coming months, the companies CRISPR Therapeutics and Vertex Pharmaceuticals will submit these treatments for regulatory approvals in Europe and the U.K.
As people of faith, what do we need to know about CRISPR, and how might Christians respond to its ethical challenges?
What is CRISPR?
CRISPR WAS ADAPTED from naturally occurring gene-editing systems that bacteria use to defend against invading viruses by adding, removing, or altering targeted stretches of DNA. When infected with a virus, certain bacteria capture snippets of the virus’ DNA and insert them into their own bacterial DNA to develop a defense. Jennifer Doudna and colleagues first published the results of an experiment on bacterial gene editing in 2012 in which they described a new method for editing DNA that could allow for changes in human genes. In 2020, Doudna and Emmanuelle Charpentier won the Nobel Prize in Chemistry for their research on CRISPR. Scientists aim to use CRISPR to correct mutations at precise locations in the human genome to treat the genetic causes of disease.
In medicine, CRISPR could advance cancer therapies by editing immune cells to attack tumors. Evolutionary biologists are using the technology to study our ancestors. Plant biologists are editing seed DNA to produce crops with new vitamins or with the ability to withstand diseases or to use less water. Because CRISPR is relatively cheap, even small labs in the Global South can create disease-resistant cassavas or drought-resistant bananas, which could benefit populations.
However, the technology is not yet accurate. Errors can occur in various phases of the editing process, whether in “cutting” or repairing the gene location. Particularly challenging is what CRISPR can cause in embryonic cells, by leading to rearrangements in the chromosomes with unknown consequences. For example, while intending to correct mutations or introduce genetic modifications, CRISPR may make mistakes and miss its intended genetic target by modifying a different gene or intervening at a different position in a gene or in several genes. Moreover, even when CRISPR is introduced right after fertilization, at the single-cell embryonic stage, its action is not necessarily immediate. The editing could occur at later stages of development. Hence, the embryos could have cells that are not genetically identical (called mosaicism). The genetic screening of embryos (performed at the 5-day stage) will not show this cell diversity because only a sample of cells is tested, which may allow incorrectly altered and unaltered cells to go undetected. Ethicists raise additional concerns regarding the respect due embryos.
Expanding the ethical scope
CRISPR CAN BE beneficial to research in various scientific disciplines and human health. It could be considered a blessing with multiple and diverse outcomes for current and future generations. As in the case of any potential blessing, advocates embrace CRISPR wholeheartedly. They turn to CRISPR as the “new grail,” as others did with recent scientific developments such as what the Human Genome Project achieved in the early 2000s. They run the risk, however, of underplaying possible hazards and limitations.
Others urge caution. They are cognizant of the dangers inherent in CRISPR and of moving it forward too quickly. They want to avoid introducing genetic mutations in living organisms that could affect delicate ecosystems. Ethicists ask for expanded protections for participants in clinical trials, and they warn about research involving embryos. Other voices invite alternative approaches to research on embryonic cells by encouraging a focus on adult cells and “induced pluripotent” stem cells (i.e., adult cells that are reprogrammed back to their early developmental state). For them, when targeting embryos, CRISPR could be a curse. They are concerned CRISPR will introduce genetic modifications in early human development that cannot be controlled and with uncertain environmental consequences. Further worries arise when genetic editing is planned on reproductive cells (gametes), which may affect both individuals and their progeny.
These diverse ways of assessing CRISPR characterize the spectrum of ethical responses currently in debate. They are focused on the technology itself. At the same time, I would propose two different and synergic perspectives that might contribute to the ethical discourse.
First, one could focus on the moral agent and on one’s own agency. For example, what does it say about us as moral agents (whether individuals or society as a whole) if one pursues CRISPR technology to eliminate a genetic mutation such as Trisomy 21 (Down syndrome)? To avoid any eugenic drive to “improve” the genetic quality of a human population, one could turn to the distinction between “therapy” and “enhancement” to find help: Research should lead to therapeutic uses of CRISPR, and enhancements should raise ethical concerns. However, it is not always easy to distinguish between the two, and careful discernment is needed.
Second, research and its applications do not occur in a social vacuum. Just as there are no private actions in biology (everything is mutually interdependent), one must recognize that the interests of private companies are not always in alignment with shared communal responsibilities. Their actions can have a grave impact on individuals, societies, and ecosystems, with little means of redress. Moreover, the world is tragically marked by profound inequities. New biotechnological developments should avoid furthering injustice in the social fabric. Progress and developments should occur in ways that foster social justice, care for the planet, and promote a vision of the common good for humankind — particularly by empowering those who are marginalized and discriminated against.
In the United States, the Food and Drug Administration regulates gene-editing technologies. In August, the FDA approved the application by U.S.-based Bluebird Bio for the first cell-based gene therapy to treat patients with transfusion-dependent beta thalassemia.
CRISPR offers challenges that call for wise discernment, to promote human and planetary well-being and foster a moral response that shows, as the prophet Micah says, the human ability to act justly, to love mercifully, and to walk humbly with God.
Andrea Vicini, SJ, is co-chair of the international network of Catholic Theological Ethics in the World Church and professor of theological ethics and bioethics at Boston College.
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