The Gene Editing Dilemma: Where Science Meets Society | Chloe Richards | TEDxKings College School

Key Concepts

• CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats): A gene-editing technology that uses a guide RNA molecule to direct the CAS9 enzyme to a specific DNA sequence, allowing for precise cuts and modifications.
• CCR5 Gene: A gene that plays a role in immune response, including resistance to certain viruses like HIV and influenza.
• Pleiotropy: The phenomenon where a single gene influences multiple phenotypic traits.
• Mitochondrial Replacement Therapy (MRT): A form of gene therapy that replaces a mother's mutated mitochondrial DNA with healthy mitochondrial DNA from a donor, preventing the transmission of mitochondrial diseases.
• Gene Editing for Enhancement vs. Therapy: The ethical debate surrounding the use of gene editing for treating diseases versus improving traits beyond normal human capabilities.

The Birth of Genetically Modified Humans and the CRISPR Scandal

On November 29, 2018, the world was alerted to the birth of the first genetically modified humans, a development that initially seemed like science fiction. The scientist responsible, He Jiankui, is now imprisoned, but the underlying technology, CRISPR, remains. Contrary to popular imagination of "designer babies" with enhanced traits, He Jiankui's experiment aimed to confer resistance to HIV. He used CRISPR to disable the CCR5 gene in the embryos of twin girls, Lulu and Nana, whose father was HIV positive.

CRISPR Mechanism Explained

The CRISPR technique involves a guide RNA molecule that binds to a target DNA sequence. This binding then directs the CAS9 enzyme to attach to and create a double-stranded break in the DNA. The cell's natural repair mechanisms then mend this break, which can involve replacing or adding nucleotides. This process can either disable a gene or introduce new DNA sequences. The analogy used is cutting and re-gluing paper; even after repair, the structure is not exactly the same as before.

Ethical and Scientific Criticisms of He Jiankui's Experiment

He Jiankui's experiment quickly became a global scandal, widely condemned as unsafe, reckless, and ethically indefensible due to several factors:

• Unnecessary Risk: The twin girls were not in extreme danger from HIV as it cannot be directly inherited through sperm and is unlikely to be passed on until after birth, a risk manageable with precautionary steps.
• Pleiotropic Effects of CCR5: The CCR5 gene has multiple functions, including reducing the risk of influenza. By disabling it, He Jiankui may have inadvertently increased the girls' susceptibility to influenza while attempting to protect them from HIV.
• Inadequate Consent: He Jiankui failed to obtain sufficient informed consent. The consent document was 23 pages long, written in English (not the first language of many participants), contained numerous technical terms, and absolved him of almost all legal responsibility for negative outcomes. This is likened to expecting someone to read lengthy, technical terms and conditions in a foreign language concerning their child's DNA.

The Future of Gene Editing: Ethical Considerations and Potential

Despite the controversy surrounding He Jiankui's actions, the prospect of gene editing is not entirely bleak. A survey indicated that 76% of the British population does not believe the technology should be banned.

Ethically Acceptable Gene Therapies

Gene therapy is already being employed in more ethically sound ways. Mitochondrial Replacement Therapy (MRT) is one such example. In MRT, the nuclear DNA from a mother's egg cell, which may contain mutated mitochondrial DNA, is transferred into a donor egg cell with healthy mitochondrial DNA. This prevents the transmission of mutated mitochondrial DNA to the child.

Pressing Ethical Questions

Even with regulated approaches like MRT, gene editing raises profound ethical questions:

• Enhancement vs. Therapy: There is a significant risk that gene editing could evolve from treating diseases to enhancing human traits, potentially creating a two-tiered society of the "edited" and "unedited."
• Value of Lives with Genetic Conditions: The pursuit of eradicating genetically inherited diseases raises the question of whether it implicitly devalues the lives of individuals currently living with these conditions.

Gene Editing as an Inevitable Future

Gene editing is presented as an undeniable part of our future. Advancements in gene therapy for conditions like Huntington's disease, a severe neurological disorder, are already being seen. While current treatments may not involve pre-birth embryo editing, this could become a future solution for eradicating such diseases entirely.

A Societal Conversation on Responsible Gene Editing

The author's personal interest in gene editing was sparked by news reports, leading to an essay on the subject. The core challenge lies in how society can responsibly utilize this powerful new technology. The key questions are:

• How can we harness this technology responsibly?
• What risks are we willing to accept to achieve a future free from genetically inherited diseases?

Gene editing is no longer solely a scientific endeavor; it requires a broad societal conversation. The call to action is for everyone to engage with the topic, learn about it, and form their own informed opinions. Staying informed is crucial for a technology that could potentially impact all members of society.

Conclusion

The birth of genetically modified humans, while a scientific milestone, highlighted the profound ethical and safety concerns surrounding gene editing technologies like CRISPR. While the technology itself holds immense potential for treating diseases, its application demands careful consideration of consent, unintended consequences, and the potential for misuse in enhancement. The future of gene editing hinges on a collective societal dialogue to ensure its responsible development and application, balancing the pursuit of a disease-free future with the ethical imperative to value all human lives and prevent societal stratification.