A Russian scientist who announced his intention to create genome-edited babies last month, has now revealed details of his plan.
Biologist Dr Denis Rebrikov said he has five couples who are deaf from Siberia, who want to have a hearing child through CRISPR genome-editing. According to New Scientist, Dr Rebrikov said he would be applying to Russian authorities for permission in a 'couple of weeks'.
'[Dr] Rebrikov is definitely determined to do some germline genome editing, and I think we should take him very seriously,' Dr Gaetan Burgio at the Australian National University in Canberra told the magazine.
Dr Rebrikov at the Kulakov National Medical Research Centre for Obstetrics, Gynaecology and Perinatology in Moscow, told Nature News last month that he wanted to implant genome-edited embryos in HIV positive mothers (see BioNews 1002). He planned to disable a gene called CCR5, which can confer resistance to the virus in individuals with a certain mutation.
This followed Dr He Jiankui's announcement of the birth of the world's first genome-edited babies in November (see BioNews 977).
Dr Rebrikov has now said he wants to use CRISPR genome-editing to correct a mutation in the GJB2 gene, which causes deafness when two copies of the mutated gene are inherited. All five couples are homozygous for the gene, so any children they have naturally will be deaf. Dr Rebrikov plans to correct one of the two mutated copies of the gene in IVF embryos from the couples.
The announcement has met with concern from the scientific community.
'Several months ago, He Jiankui opened a Pandora's box with the first genome-edited embryos using CRISPR,' said Dr Dusko Ilic, a stem cell scientist at King's College London. 'To me this suggestion looks like another scientist jumping the gun and wanting to be first, ignoring basic safety measures and using desperate people as guinea pigs.'
Sarah Norcross, director of the Progress Educational Trust (which publishes BioNews) said: 'It is to the credit of Denis Rebrikov that he is at least discussing openly his plans to use germline genome editing…This is far preferable to the secretive manner in which Dr He Jiankui acted last year.'
She added: 'Nonetheless, Dr Rebrikov is proposing to do this in the face of a strong scientific consensus that such germline genome editing is not yet ready for use in the clinic, because questions of safety and efficacy – not to mention ethics – have yet to be resolved satisfactorily.'
Others raised specific concerns that genome-editing could have unintended effects. Professor Darren Griffin at the University of Kent in Canterbury said: 'We really need to establish, using embryos donated for research, that there are no off-target effects of this sort of treatment.'
Dr Lydia Teboul at the MRC Harwell Institute in Oxfordshire, noted: 'Our collective experience with laboratory animals clearly says that the outcome of genome editing in embryos is unpredictable and error prone.'
'Also, mutations in the gene chosen as a target, GJB2, are linked to other diseases that affect eyes and skin and are associated with a higher risk of cancer,' she added. 'Any sort of modification of the action of this gene could potentially be risky to human health.'