Monday, October 21, 2019

Using CRISPR to edit eggs, sperm, or embryos does not save lives

Some scientists hail reproductive applications of CRISPR as potentially lifesaving and curative. That claim for CRISPR is mistaken and misleading.


This startling announcement by He Jiankui almost one year ago that he had created the first genetically modified human beings unleashed a torrent of criticism. It also brought to the surface common misunderstandings — even among scientists and ethicists — that reproductive uses of this genome-modifying tool have therapeutic value, will treat people with genetic disorders, will save lives, and will eradicate disease. None of those are true.



The twin girls that He helped create are publicly known as Lulu and Nana. Their father is HIV-positive. The scientist said he used CRISPR-Cas9 genome editing technology to disable a gene called CCR5 to mimic a naturally occurring gene deletion that appears to confer immunity against HIV.



In a recent publication, The  Journal of Bioethics the ethics and thinking behind this ill-advised experiment are viewed by another expert.

A major criticism from the scientific community, which has otherwise been generally supportive of advancing gene technologies, was that He did not use the technology to address a serious medical need. That criterion stems from a 2017 report by the U.S. National Academy of Sciences and the National Academy of Medicine recommending that, once the technology is ready and safe, genetic modification of embryos could be allowed when there is a “serious disease or condition” to be addressed and no “reasonable alternatives” exist.


IVF with pre-implantation genetic diagnosis is an existing alternative to CRISPR for preventing the transmission of genetic disease.
PHILIPPE LOPEZ/AFP VIA GETTY IMAGES

This scientific criticism of He’s experiment was on target: Although HIV infection is a serious disease, there are proven ways to prevent transmission of the virus from an infected father to his offspring, and later in life to prevent or treat the infection.

This act can be compared to the young child finding a gun and shooting itself because it did not understand what a gun does.  It's actions cannot be reversed....the genie is out of the bottle.

Careful consideration must be taken when designing and proposing gene editing using CRISPR or any other techniques which alter the 'germ line' of human and mammalian cells. We know so little about the long term effects of clipping out parts of the gene or adding snippets.  If there are other methods of treatment with known risks, they should always be used first. "primum non nocere" is one of the first things that medical trainees are taught.


Although we 'think' we know how genetics works and how DNA fits into programming protein manufacturing each year that goes by new surprises appear to disprove our theories.

CRISPR does offer a new tool for research in laboratory animals, bacteria, viruses.  Unique genes  can be inserted to use microorganism's machinery to manufacturer new drugs.

"Prime editing" is more precise and more efficient than CRISPR and could herald a new era of genetic manipulation.




Using CRISPR to edit eggs, sperm, or embryos does not save lives - STAT:

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