The successful development of the revolutionary gene-editing technology called CRISPR won the 2020 Nobel Prize in Chemistry, awarded to Emmanuelle Charpentier of the Max Planck Institute, and Jennifer Doudna of the University of California, Berkeley.
CRISPR offers the exciting possibility of developing new gene therapies – treatments involving genome editing to prevent/treat human diseases that have a genomics basis, such as cystic fibrosis, diabetes, muscular dystrophy, sickle-cell anaemia and more. Unfortunately, CRISPR could also be used to achieve bad ends, such as being used in misguided eugenics programmes.
CRISPR stands for “clustered regularly interspaced short palindromic repeats”, and is a natural molecular technology used by many bacteria to fight off invading viruses. This molecular technology can also be used in mammalian cells to edit genetic DNA by adding, removing or changing DNA letters, and by turning genes on/off without altering their sequence.
Although there are other means of carrying out gene therapy, CRISPR has opened up new possibilities for treating human genetic diseases, is faster and much cheaper than other gene-editing technologies, and has revolutionised biotechnology. Last year the world’s first CRISPR therapy was approved to treat human patients with sickle-cell disease.
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Any ideas of modifying the evolution of society through genetic manipulation resonate with the views of Francis Galton (1822–1911) – of guiding human evolution through controlled breeding, also known as eugenics. Not only were Galton’s ideas based on false evidence, but they led on to disastrous programmes of mass sterilisation and eventually to the genocidal nightmare of the Nazi gas ovens.
Engineering inheritable genetic changes to produce what might be seen as socially desirable traits that are not disease-related in future generations, such as light skin colour, is problematic
CRISPR should be used to pioneer cures for diseases while upholding human dignity and sanctity of life for all. We must be extremely cautious and conservative about using CRISPR to manipulate the genetic make-up of future generations. Human diversity of cultures, perspectives, abilities and identities are vitally important for global equilibrium and functioning, and we interfere with this diversity at our peril.
A reasonable person might think it would it be a good idea to use CRISPR to eliminate disease-related genes from the human genome, eg genes that predispose people to heart disease, obesity and type 2 diabetes. However, there is mounting evidence that these genes conferred advantages related to survival upon our ancestors prior to the Industrial Revolution, when nutrition was generally poor and patchy (see the views of Maria Esther Rubio Ruiz and others in International Journal of Evolutionary Biology).
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Today, many people eat highly processed foods rich in fat/sugar while at the same time leading sedentary lives, a combination that interacts with these old survival-enhancing genes to cause deadly modern diseases. So, in a future world possibly bedevilled by famines and other privations, these “bad genes” could actually function as “good genes“. It would be unwise to eliminate them from the population now.
Also, engineering inheritable genetic changes to produce what might be seen as socially desirable traits that are not disease-related in future generations, such as light skin colour, is problematic. Many non-westerners use skin-whitening cream to induce fair complexions, believing fair skin looks better than dark skin. But genetically engineering fair skin in offspring could put them at a future disadvantage in terms of survival. If atmospheric ozone levels deplete significantly, genetically engineered fair-skinned people, who would otherwise be protected by skin melanin, would suffer increased incidence of skin cancer.
A global moratorium on heritable gene-editing was introduced in 2019. This moratorium will end soon
In 2018, maverick Chinese scientist He Jiankui carried out unregulated gene editing of human embryos, two of whom were later born as the twin girls Lulu and Nana. This genetic editing was designed to confer resistance to the Aids-inducing human immunodeficiency virus (HIV) by inactivating the gene CCR5, mimicking a natural mutation that protects a small number of people from HIV.
This work was greeted with worldwide concern. Scientists pointed out that too little is known about genes to make such changes safely, that other genes can be damaged in the process, and that these changes are passed on to future generations. A global moratorium on heritable gene-editing was introduced in 2019. This moratorium will end soon, and anxieties regarding what CRISPR technology might lead to are mounting.
While CRISPR technology promises wonderful advances in medicine, it also raises profound ethical questions. Going forward, we must remain vigilant in guarding human rights and ethical practices that support equality and dignity of all, regardless of their genetic make-up. No less than the aforementioned Doudna, one of the inventors of CRISPR technology, has called for a ban on heritable gene-editing until scientific, technical and ethical questions are answered and public consensus has developed.
William Reville is an emeritus professor of biochemistry at UCC