Human embryos genetically changed by Chinese scientists

Published Date
Ozge Ozkaya

For the first time, scientists in China have published results on new technology for changing the genome of human embryos. The aim of their research was to test a technique that might be able to repair genetic mutations and treat inherited diseases at an early stage. The results were published in the online journal Protein and Cell and have sparked major concerns in the scientific community about the ethics of this research.

The researchers used embryos from local fertility clinics that were produced during IVF but were not viable. They injected a protein complex called CRIPSR/Cas9 that can bind to and cut DNA at specific locations into the embryos. The protein complex was designed to specifically correct a mutation in the gene causing ß-thalassaemia, an inherited blood disorder.

However, the results of the research show that the CRIPSR/Cas9 system is not working efficiently as the genetic mutation was successfully corrected in only a small fraction of the embryos. Moreover, the scientists observed a large number of “off-target” genetic mutations on other parts of the genome which could be harmful. Huang and his team indeed stated that their results reveal serious obstacles to using the method in medical applications.

This technique has previously been studied in human adult cells and animal embryos. However this is the first report of it being applied to human embryos. While some scientists think this technology might have great potential to correct genetic mutations before a child is born, others have warned of the ethical implications. The genetic changes in the embryos are heritable and there are concerns over unpredictable effects these changes could have on future generations.

Research into the genetic modification of embryos (also known as germline modification) is illegal in the UK and Muscular Dystrophy UK does not fund any such research. The charity does support research into developing technologies to correct genetic defects in adult cells as they have great potential to treat people affected by muscular dystrophy and related conditions. Read more about Prof George Dickson’s project on “Genome surgery for Duchenne muscular dystrophy”.

The charity is supporting the call from a group of leading scientists including Nobel laureate Professor David Baltimore and an inventor of the CRIPSR/Cas9 system to set up a world-wide moratorium on the manipulation of the human germline. They recommend research into germline modification for clinical use should be strongly discouraged, including in those countries where a lax law might permit such research. This will allow ethical implications and the impact on society and the environment to be fully considered.

The group also calls for transparency on research into the efficiency and precision of the CRIPSR/Cas9 system. And they recommend making available information about the risks and benefits of introducing such technology into the clinic.

They have also called for the establishment of a representative group involving researchers working on the development of these techniques; experts in genetics, law and bioethics; other members of the scientific community, the public, relevant government agencies and interest groups; to consider together these important issues and recommend policies.          

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