tech2 News StaffJul 31, 2019 17:54:16 IST
In December 2018, a Chinese scientist made a bold claim that he had secretly edited the genes of embryos. Not just that, he also claimed to have implanted these gene-edited embryos into seven couples undergoing IVF — two of the couples went on to be pregnant. One of the two couples successfully delivered their babies — twin girls, who He Jiankui, the Chinese geneticist that led the gene-editing trial, said were given natural resistance to the human immunodeficiency virus (HIV) infection caused by the acquired immunodeficiency syndrome (AIDS) virus. For more than one reason, Jiankui's claim created quite a stir in the scientific community.
The World Health Organization, the leading authority in global public health, released a statement on 26 July stating its qualms with the practice of gene editing in humans. "It would be irresponsible at this time for anyone to proceed with clinical applications of human germline genome editing," Dr Tedros Adhanom Ghebreyesus, WHO Director-General, said during a committee meeting.
The WHO has asked that regulatory and ethics authorities in all countries put a stop and deny approvals to gene editing experiments that could lead to babies being born with gene-edited DNA (a process known as germline gene-editing, where the modified DNA is passed on from generation to next). This limitation will last till a time when the "implications have been properly considered," since gene editing in humans presents unique and unprecedented ethical and technical challenges, the WHO director-general said.
The recommendation comes from an 18-member expert advisory committee to the WHO on human genome editing, formed in December after news about Dr He Jiankui's gene-editing trials first surfaced. The committee also suggested that WHO create a global registry of all experiments involve genome editing, and human genome editing in particular.
The matter will be revisited during a WHO meeting in Geneva in August 2019. They will also look into the instruments that can deter and prevent irresponsible and unacceptable uses of genome-editing in embryos before implantation and pregnancy. Some scientists have announced their support for the strong words from WHO.
Fyodor Urnov, a gene-editing scientist at the Altius Institute for Biomedical Sciences in Seattle and the University of California, Berkeley said to Wired, "I commend the WHO for taking a stance on what I think is the right side of the issue."
Others, like Jiankui, believe they should be allowed to conduct gene-editing studies, even if regulated, with human embryos. Dr George Church, a Harvard geneticist, in an interview with The Associated Press, defended He Jiankui's attempt to edit vulnerability to HIV from human DNA, calling it "justifiable" since HIV is "a major and growing public health threat."
UNESCO, too, has called for a ban on the editing of human DNA and tampering with traits that are hereditary. Parents of the twin baby girls, who allegedly had their DNA edited using a gene-editing technology called CRISPR, do not want to be identified or interviewed, according to Jiankui. There is no official paperwork published in a scientific journal to vet Jiankui's attempt at giving the twins resistance to HIV using CRISPR.
CRISPR-Cas9 is a tool that makes it possible to operate on DNA — either to add a much-needed gene or to disable one that's causing a problem. The technology has been used in adults to treat deadly diseases. While there are ethical issues involved in using gene editing to treat adults, too, the effects of the treatment at adulthood will likely be confined to that person alone, and not passed on to their future generations. The lack of long-term safety data for the effects of CRISPR in humans is responsible for the ethical grey area around gene-editing and CRISPR's clinical applications.
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