Subscribe to the BioNews newsletter for free

Login
Advanced Search

Search for
BioNews

Like the Progress Educational Trust on Facebook




 

Second Chinese team create genetically modified human embryos

11 April 2016

By Ayala Ochert

Appeared in BioNews 846

A second team in China report that they have created genetically modified human embryos, in an attempt to make them resistant to HIV, using the genome-editing technique CRISPR/Cas9.

Last April, a different Chinese team reported the first-ever genetically edited human embryos (see BioNews 799), generating widespread debate about human germline modification (see BioNews 831).

The research team, led by Dr Yong Fan of the Guangzhou Medical University in China, used CRISPR/Cas9 to introduce a particular mutation into the CCR5 gene. People with this mutation are known to be resistant to HIV infection because the altered CCR5 protein prevents the virus from entering T cells.  

The study, published in the Journal of Assisted Reproduction and Genetics, involved 213 human embryos donated by patients undergoing IVF. The embryos could not be used for fertility treatment as they each had extra set of chromosomes and so were not viable.

Dr Fan and this team performed the CRISPR technique on 26 embryos but found that this resulted in only four containing the intended CCR5 mutation. Even in those cases, the mutation was not found in all the embryo's cells. The researchers also detected 'off-target' effects, with unintended mutations being picked up in other locations in the genome.

The embryos were all destroyed after three days.

The researchers acknowledge the ethical issues involved, but argue that this type of proof-of-principle research should continue while these are debated. 'We believe that any attempt to generate genetically modified humans through the modification of early embryos needs to be strictly prohibited until we can resolve both ethical and scientific issues,' they write.

'This paper doesn't look like it offers much more than anecdotal evidence that it works in human embryos, which we already knew. It's certainly a long way from realising the intended potential [of a human embryo with all its copies of CCR5 inactivated],' Professor George Daley, a stem-cell biologist at Children's Hospital Boston in Massachusetts, told Nature News.

In January, Dr Kathy Niakan of the Francis Crick Institute was given permission by the HFEA to use CRISPR to begin genetically editing human embryos in order to research the mechanisms of early miscarriage (see BioNews 837). But Professor Daley says that Dr Niakan's research is intrinsically different because it's about answering fundamental questions of embryology, whereas Dr Fan's is about generating an individual with resistance to HIV. 'That means the science is going forward before there's been the general consensus after deliberation that such an approach is medically warranted,' said Professor Daley.

RELATED ARTICLES FROM THE BIONEWS ARCHIVE

07 August 2017 - by Charlotte Spicer 
Scientists have published their study confirming they are the first to correct a disease-causing mutation in human embryos using genome editing...
31 July 2017 - by Charlotte Spicer 
Scientists in the US may have successfully used genome editing in human embryos to correct disease mutations, according to a report by MIT Technology Review...
13 March 2017 - by Dr Katie Howe 
Chinese scientists have successfully used genome editing to correct mutations in viable human embryos for the first time...
26 September 2016 - by Anneesa Amjad 
A scientist in Sweden has become the first to edit genes in healthy human embryos...
25 July 2016 - by Rachel Siden 
Chinese scientists plan to start the first-ever clinical trial of CRISPR genome-editing technology in humans – on patients with lung cancer – this August...

11 April 2016 - by James Brooks 
Scientists testing whether the CRISPR genome-editing technique could effectively kill HIV in infected cells have found that, while the approach works in most cases, it can also cement the virus's presence...
04 April 2016 - by Dr Lanay Griessner 
Scientists have used the CRISPR genome-editing technique to remove HIV from the DNA of infected T cells and prevent reinfection...
01 February 2016 - by Ayala Ochert 
The Human Fertilisation and Embryology Authority has granted the first licence to a UK researcher to edit the genomes of human embryos...
18 January 2016 - by Dr Jess Buxton 
We report from the third session of the annual conference of the Progress Educational Trust, titled 'Genome Editing and CRISPR: The Science of Engineering the Embryo', which discussed these new technologies and how they might be used in the future...
07 December 2015 - by Dr Jane Currie 
An international summit has agreed conditions under which human genome editing, using techniques like CRISPR, should proceed...

HAVE YOUR SAY
Be the first to have your say.

You need to or  to add comments.

By posting a comment you agree to abide by the BioNews terms and conditions


- click here to enquire about using this story.

Published by the Progress Educational Trust
Advertise your products and services HERE - click for further details

Good Fundraising Code

Become a Friend of PET HERE and give the Progress Educational Trust a regular donation