Concerns mount over DNA editing technology
From designer babies to engineered mosquitoes, advances in genome-editing technologies such as CRISPR–Cas9 have raised the possibility of tremendous scientific advances and serious ethical concerns.
Clustered Regularly Inter-spaced Short Palindromic Repeats (CRISPR) refers to unusual Deoxyribonucleic Acid (DNA)/genetic material sequences that help protect organisms by identifying threats – especially viruses – and attacking them.
An international summit on human gene editing last year recommended that such fundamental research could and should be done, given proper scientific justification and ethical oversight. But many people worry that such research, especially on viable embryos, opens the door to creating designer babies and forever altering the genetic heritage of humans.
A new report has warned that amateur scientists toying with powerful gene editing technology in their garages could pose a future risk to human health and the environment.
It highlights a growing trend for so-called ‘biohackers’ who use new technology to modify the DNA in living organisms outside of traditional research institutions.
While most of these groups of amateur researchers are attempting to solve problems like creating new flavours of beer, some could do more harm.Gene therapy has historically been defined as the addition of new genes to human cells. However, the recent advent of genome-editing technologies has enabled a new paradigm in which the sequence of the human genome can be precisely manipulated to achieve a therapeutic effect. This includes the correction of mutations that cause disease, the addition of therapeutic genes to specific sites in the genome, and the removal of deleterious genes or genome sequences.
A review published in the journal Molecular Therapy presents the mechanisms of different genome-editing strategies and describes each of the common nuclease-based platforms, including zinc finger nucleases, transcription activator-like effector nucleases (TALENs), meganucleases, and the CRISPR/Cas9 system.
The study is titled “Genome-editing Technologies for Gene and Cell Therapy.”The report by the Nuffield Council on Bioethics points to £100 kits that can effectively ‘cut and paste’ DNA in yeast or bacteria to alter their properties.
The DNA editing technology, CRISPR-Cas9 technology, precisely changes target parts of genetic code.Unlike other gene-silencing tools, the CRISPR-Cas9 system targets the genome’s source material and permanently turns off genes at the DNA level.
The DNA cut – known as a double strand break – closely mimics the kinds of mutations that occur naturally, for instance after chronic sun exposure.But unlike Ultra Violet (UV) rays that can result in genetic alterations, the CRISPR-Cas9 system causes a mutation at a precise location in the genome.
When cellular machinery repairs the DNA break, it removes a small snip of DNA. In this way, researchers can precisely turn off specific genes in the genome.
This technology, known as CRISPR-Cas9, can be used without needing a high level of scientific knowledge, unlike other gene editing techniques, which need expensive equipment and specialist training.
The Nuffield Council on Bioethics said the ‘comparatively low cost, ease of use and availability’ of these new gene editing kits, which can be purchased online, meant they were accessible to unregulated users. This raises the prospect that scientists could either deliberately or accidentally create an organism that could be harmful if released into the environment.
It added: “These may include DIY ‘garage’ scientists, school and undergraduate students, and others with an interest in biological research and the possibilities – whether potentially beneficial or harmful – raised by genome editing.”
The report comes just weeks after a leading molecular biologist at Oxford University warned that the technology could be used to develop new types of biological weapons.
Indeed the Federal Bureau of Investigation (FBI) is so concerned about the activities of biohackers it has set up a special branch within its Weapons of mass Destruction Directorate to engage with them.
There is a flourishing biohacking community in many parts of the world with amateur groups getting together to develop homemade approaches to studying biology.CRISPR-Cas9 was introduced in 2012 and is rapidly transforming biological research.
The system uses certain proteins that allow DNA to be cut and edited at precise, targeted locations.The Nuffield Council identified human reproduction and livestock farming as two key areas of concern. Both will be the subjects of further inquiries by dedicated working parties.
In the field of human reproduction, gene editing has the potential to eliminate inherited diseases such as cystic fibrosis.There are more than 4,000 known single gene conditions that are thought to affect around one per cent of births worldwide.But producing babies from embryos whose inherited DNA has been altered is illegal in the UK and still highly controversial.
Critics point to the dangers of irreversible changes being passed onto future generations and the possible creation of ‘designer babies’.Genome editing in farm animals has already been proposed for pigs, sheep, cattle and chickens, raising questions of food safety and animal welfare.Animals whose genes have been edited may fall into a grey legal area because it is not clear that their meat, eggs or milk would be classified as genetically modified food.
Potential applications of the technology-included pigs protected against swine flu, chickens that only produced female offspring for egg production, and hornless cattle that could safely be kept in confined spaces.
Although gene editing was already racing through research laboratories, the revelation in 2015 that researchers had used CRISPR–Cas9 in human embryos shone a public spotlight on its potential applications in human reproduction. That first study used non-viable embryos for research purposes only, but it launched a public debate about whether and how such technologies should be deployed in humans.
In parallel, an independent group of European ethicists has called for the formation of a European steering committee to discuss standards to ensure that CRISPR methods are safe and reliable before being used for medical purposes. The team has started discussions with the European Commission about this, says François Hirsch, assistant director for ethics and regulation at the Institute for Health Technologies in Paris, who co-authored a white paper calling for the committee.
The Nuffield Council aims to finish its report on ethical questions in human reproduction in early 2017. The working group will focus on the implications of using gene editing to address genetic diseases.
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