In a 2016 Ted talk of Jennifer Kahn, she described gene editing as a powerful tool, yet an alarming one. Gene editing (also known as genome editing or genome engineering) is the act of insertion, deletion, or alteration of an organism's DNA by modifying particular areas in the genome. Several techniques in gene editing have been developed, including CRISPR (clustered regularly interspaced short palindromic repeats). CRISPR is associated with an enzyme called Cas-9 or a similar enzyme that acts as a pair of molecular scissors and is used to cut or add selected sections of DNA.
Uses of CRISPR nowadays include: making a new and improved fruit like groundcherry, changing flowers from violet to white, and even modifying human embryos paving the way for what we call - the world's first gene-edited babies.
In a 2018 gene-editing summit, Chinese researcher He Jiankui has announced that he used CRISPR editing technique to change the DNA of human embryos, modifying the CCR5 gene to make the offspring resistant to HIV. This eventually led to the birth of the twins, namely Lulu and Nana. This act has received numerous reactions and criticisms from scientists worldwide.
The interviews done by AP involved one with Jennifer Doudna, a biochemist at the University of California, Berkeley, and a pioneer of CRISPR-Cas9 gene-editing technique. In the interview, Doudna said she was grateful that He came in the summit as scheduled, but there were still a lot of unanswered questions such as the monitoring method for the gene-edited babies. Understanding the motivation of He's study and knowing the process of the informed consent are still yet to be explored.
In addition, Massachusetts Institute of Technology (MIT) Professor Richard Hynes mentioned in the interview that there are alternative ways to protect the babies from HIV which could have been easier and better without posing risks to the babies. Hynes also questioned the method of how the informed consent was done: "I don't think this should have been done, I think it's unfortunate," he added.
Also, Harvard University Professor David Liu added, "The process by which these patients were treated was without the engagement of critical stakeholders including independent scientists, ethicists, regulatory committees, governing bodies, and such." For Liu, it is an example of what not to do with a new technology that has incredible potential to benefit society.
The reactions of the scientific community regarding He's experiment was also shown in China. Last 30 December 2019, the Chinese court has sentenced He for 3 years in prison with a fine of 3 million yuan (US$430, 000) due to violation of medical regulations related to his gene-edited babies experiment. His two collaborators Zhang Renli and Qin Jinzhou, were also sentenced and received lesser fines.
In the point of view of the majority, including the scientific community, the notion of experimentations involving human beings is considered unethical. It is especially valid when there is a lack of evidence to support claims that the experiment will produce positive results or any harm would not be encountered.
In a background paper by Cavaliere in 2019, concerns in He's experiment evolved within the lack of safety assessments and thorough ethical review process. Moreover, concerns on the adequacy in the process of the informed consent document signed by the parents and the exposure of the twins to the risk of the genome were also raised.
He's experiment has used human germline gene-editing which poses a risk where any changes made in the germlines (involvement of sperm or egg cells) will be hereditary; thus, each process involved should have strictly followed international standard protocols.
In line with this, the US National Institutes of Health (NIH) and CRISPR experts initiated a call for a global moratorium on heritable gene-editing of human germlines. One of the initiators of the moratorium is Feng Zhang, a member of the Broad Institute of MIT and Harvard and one of the inventors of the CRISPR editing technique. The proposal focused on the adoption of an international governance framework for future researches in the area of human germline gene-editing.
At the moment, there is not enough evidence to support that the use of CRISPR technique is safe. Its effects on the involved humans and future generations are yet to be discovered.
Everyone - scientists, authorities and the public, should know as much as possible about the risks of gene-editing human embryos before such research can proceed. At the same time, the potential benefits of this type of research should be looked at and considered. Nevertheless, decisions and actions should be made with accompanying caution and responsibility.
What are your thoughts about CRISPR-Cas9 / human germline gene-editing?
How do you respond to He's experiment, the world's first gene-edited babies?
Let us know your thoughts through the comments section below!
Readings / Video Sources:
1) TED. Gene editing can now change an entire species – forever | Jennifer Kahn. Retrieved from: https://youtu.be/OI_OhvOumT0
2) Judit Sándor. Human Embryos and Preimplantation Genetic Technologies. Retrieved from: https://www.sciencedirect.com/book/9780128164686/human-embryos-and-preimplantation-genetic-technologies
3) Aparna Vidyasagar. What is CRISPR? Retrieved from: https://www.livescience.com/58790-crispr-explained.html
4) Genetics Home Reference. What are genome editing and CRISPR-Cas-9? Retrieved from: https://ghr.nlm.nih.gov/primer/genomicresearch/genomeediting
5) Emily Mullin. The 7 Craziest Ways CRISPR Is Being Used Right Now. Retrieved from: https://onezero.medium.com/the-7-craziest-ways-crispr-is-being-used-right-now-bcf3bd203f23
6) David Cyranoski. CRISPR-baby scientist fails to satisfy critics. Retrieved from: https://www.nature.com/articles/d41586-018-07573-w
7) Wellcome Sanger Institute. Genome damage from CRISPR/Cas9 gene editing higher than thought. Retrieved from: https://www.sanger.ac.uk/news/view/genome-damage-crisprcas9-gene-editing-higher-thought
8) AP Archive. Questions grow in HKong on claim of gene-edited babies. Retrieved from: https://www.youtube.com/watch?v=A4Rfnh7ud3k
9) The Guardian. Chinese scientist who edited babies’ genes jailed for three years. Retrieved from: https://www.theguardian.com/world/2019/dec/30/gene-editing-chinese-scientist-he-jiankui-jailed-three-years
10) Niall Firth. CRISPR experts are calling for a global moratorium on heritable gene editing. Retrieved from: https://www.technologyreview.com/2019/03/13/136623/crispr-experts-are-calling-for-a-global-moratorium-on-heritable-gene-editing/
11) Antonio Regalado. CRISPR inventor Feng Zhang calls for moratorium on gene-edited babies. Retrieved from: https://www.geneticsandsociety.org/article/crispr-inventor-feng-zhang-calls-moratorium-gene-edited-babies
12) Joel Achenbach. NIH and top scientists call for moratorium on gene-edited babies. Retrieved from: https://www.washingtonpost.com/science/2019/03/13/nih-top-scientists-call-moratorium-gene-edited-babies/
13) Giulia Cavaliere. Background Paper: The Ethics of Human Genome Editing. Retrieved from: https://www.who.int/ethics/topics/human-genome-editing/WHO-Commissioned-Ethics-paper-March19.pdf