Today, Explained: Baby’s First Gene Edit

Episode Overview: In the June 5, 2025 episode of Today, Explained, hosts Sean Rameswaram and Noel King delve into the groundbreaking case of Baby KJ, the first infant to receive a gene-editing treatment using CRISPR technology. This episode explores the scientific advancements that made this possible, the emotional journey of KJ's family, and the ethical implications surrounding gene editing in humans.

1. The Miracle of Baby KJ

Introduction to Baby KJ: The episode opens with the heartwarming story of Baby KJ, who spent his first year in the Children's Hospital of Philadelphia due to a rare genetic disease. At approximately one in a million, KJ's condition was deemed untreatable until an unprecedented genetic treatment became available.

Family's Journey: Becca Muldoon shares the harrowing moments leading up to KJ's diagnosis and treatment:

“Within 48 hours, a nurse pulls Kyle aside and discovers KJ's ammonia levels are dangerously high” (02:25).

The Decision for Gene Editing: Facing the choice between a liver transplant and an experimental gene-editing treatment, KJ's parents opted for the latter:

“We had to give him this medicine that's never been given to anybody before. It was an impossible decision” (03:19).

2. Scientific Breakthrough and Treatment Process

Advancements in Gene Editing: Becca elaborates on the decade-long advancements in CRISPR technology that enabled KJ's treatment:

“Researchers have been preparing for a baby like KJ because of all these advancements in gene editing” (04:07).

Rapid Development and Testing: The team conducted accelerated "time trials" to develop the treatment within six months, collaborating with researchers and companies across the U.S.:

“We have to act quickly if we're going to make a difference in the lives of these babies” - Jason Mast (04:52).

Administration of the Treatment: KJ received three doses of the gene-editing therapy over a few weeks. After the second dose, significant improvements were observed:

“We were able to really lower the medications he had been on to control ammonia” (06:10).

Technical Explanation: Becca explains the CRISPR mechanism used:

“There's a delivery vehicle called a lipid nanoparticle... inside of that you put a gene editing protein and a guide RNA” (07:21).

3. Ethical Considerations and Future Implications

Cost and Accessibility Concerns: Becca addresses the challenges of scaling this treatment:

“It definitely cost millions of dollars... where is the money to make this at scale?” (10:01).

Limited Applicability: Currently, gene editing is feasible for only a few types of conditions:

“You can do it with conditions that affect the liver... pretty much anything else is more complicated” (10:03).

Potential for Wider Use: While KJ's case is promising, the scalability and broader application of gene editing remain uncertain:

“There's no one pulling up that money to make that at scale for thousands of infants” (10:03).

Ethical Debate: The episode shifts to the controversial topic of germline gene editing, highlighting the case of the CRISPR babies in China:

“No babies should be born at this point in time following the use of this technology” - Francoise Baylis (18:13).

Global Regulation: Kyle Muldoon discusses the global stance on gene editing:

“About half of the world's countries explicitly prohibit this kind of research” (22:03).

Future Conversations: The hosts emphasize the need for ongoing dialogue about the ethical use of gene editing:

“There will be conversations about how much testing you do and what is safe” (11:37).

4. The CRISPR Babies Controversy

Overview of the CRISPR Babies: The episode recounts the 2018 incident in China where embryos were genetically modified to resist HIV, resulting in the birth of twin girls, Lulu and Lala:

“They are the first genome-edited children and are referred to as the CRISPR babies” (16:18).

Bioethical Perspectives: Francoise Baylis criticizes the premature use of gene editing in embryos:

“It's cowardice to seek permission from 30 governing bodies before taking every step” (17:40).

Scientific Community's Reaction: While some scientists advocate for the potential benefits, the majority view such actions as ethically problematic:

“A small pocket of people say this is important progress, but it’s deeply problematic” (18:20).

5. Looking Ahead: Therapeutic vs. Enhancement

Therapeutic Applications: Kyle Muldoon posits that therapeutic gene editing, like KJ's case, has a place but is distinct from enhancements:

“If you're looking at therapeutic interventions, the number of persons that you would create is infinitesimally small” (22:52).

Enhancement Risks: The episode warns against the potential misuse of gene editing for non-therapeutic enhancements, raising concerns about "superhumans" and unintended consequences:

“You are trying to take over the human evolutionary story” (22:52).

Societal Impact: The hosts highlight the necessity for regulations and ethical guidelines to navigate the complexities of gene editing:

“We can’t know what the future will bring... we need to have these conversations” (22:52).

Conclusion

Today, Explained provides a comprehensive exploration of Baby KJ's gene-editing treatment, showcasing both the incredible scientific advancements and the profound ethical dilemmas they introduce. As gene editing technology continues to evolve, society faces pivotal decisions about its application, accessibility, and moral boundaries.

Notable Quotes:

• Becca Muldoon (02:25): "Within 48 hours, a nurse pulls Kyle aside and discovers KJ's ammonia levels are dangerously high."

• Francoise Baylis (18:13): "No babies should be born at this point in time following the use of this technology."

• Kyle Muldoon (22:52): "What else could you do that might have a more important impact over time?"

Credits: Produced by Victoria Chamberlain, edited by Miranda Kennedy, fact-checked by Abishai Artsy, and mixed by Patrick Boyd and Andrea Christensdottir. Special thanks to bioethicist Francoise Baylis for her insights.