A Chinese scientist has announced that he edited the genomes of two human embryos to make them resistant to HIV. And that he had implanted these embryos in their mother, who gave birth to healthy twin girls last November. Jiankui He used CRISPR/Cas9, which according to yourgenome.org is the “most common, cheap and efficient system used for genome editing.” So we now have at least (are there more out there that we don’t know about?) two human beings, with altered genomes on the planet. Have we opened Pandora’s box? Are we on our way to Gattaca?
Let’s discuss the ethics of genome editing at the #HealthXPH tweet chat on December 8, 9 pm Manila time.
T1. Do you agree with editing the human genome? If yes, under what circumstances? If no, why?
The father of the CRISPR-edited babies had HIV, but the mother did not. Was this a life-saving procedure for the twin girls? It has been argued that the babies did not have HIV and that there were safer ways to prevent them from getting it.
And then there’s Gattaca. Marcy Darnovsky, executive director at the Center for Genetics and Society has argued to ban human embryo editing –
We’re living in a time when racism and socioeconomic disparities are increasing dramatically. The last thing we need is for some biological procedure to fuel the false idea that some groups are biologically superior to others.https://www.sciencenews.org/article/chinese-scientists-raise-ethical-questions-first-crispr-gene-edited-babies
T2. If the CRISPR-edited babies are otherwise healthy, does this justify what the researcher did?
How often have we heard this? Just because you can, doesn’t mean that you should. It is sobering to realize that the genetic alterations of the CRISPR-edited babies will also be inherited by their offspring.
Gene editing has been attempted for Hunter syndrome. This is a rare genetic disorder where an enzyme deficiency leads to accumulation of glycosaminoglycans in the body, damaging many organs. Those with severe disease may not survive beyond their teen years. Weekly infusions of the missing enzyme have helped some of those suffering from the disease. A clinical trial was launched in 2017 using zinc finger nucleases (not CRISPR) to insert a healthy version of the gene in the patient’s genome. The trial has had mixed results.
How does this trial differ from Dr. He’s? He disabled a normal gene.
Instead, Dr. He went ahead and disabled a perfectly normal gene, CCR₅. While people who are born with both copies of CCR₅ disabled are resistant to H.I.V., they are more susceptible to West Nile virus and Japanese encephalitis.https://www.nytimes.com/2018/12/05/health/crispr-gene-editing-embryos.html
By implanting the genetically-modified embryos, Dr. He also broke the law. The US FDA has classified implanting these embryos as akin to introducing a new biological product in human subjects, and is not accepting applications involving such embryos for research.
China does not have an explicit ban on using gene editing on embryos for reproduction, but the ministry of science and technology and the ministry of public health have issued ethical guidelines, stating that no human embryos used for research can been be implanted in humans or animals for reproduction.https://www.theguardian.com/world/2018/nov/27/china-orders-inquiry-into-worlds-first-gene-edited-babies
T3. Is it possible to get informed consent for genome editing, when consequences remain mostly unknown?
The ethical practice of medicine requires informed consent. This means explaining to patients the possible risks and benefits of what is to be done. He/she must be able to understand and accept the risks.
It’s not clear if the participants in He’s trial were actually aware of what they were signing up for. He relied on an AIDS association to reach out to the patients and falsely described his work as an “AIDS-vaccine development project.https://www.theatlantic.com/science/archive/2018/12/15-worrying-things-about-crispr-babies-scandal/577234/
Genome editing is relatively new, that even the scientists doing work in this field don’t know all the risks.