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10 NOVEMBER 2019

CRISPR/Cas9: The biological “mixed blessing”

of the 21st century

What are the frontiers of human interference with nature? This is the question I ask myself when I come across research papers or news focused on the genome-editing potential of CRISPR/Cas9. To begin with, however, what does  this fancy name stand for? CRISPR/Cas9 is a defence mechanism utilized by bacteria to protect themselves against foreign DNA. This complex is part of the acquired immunity of bacteria that allows them to detect, cut and degrade DNA deriving from viruses. The ability of CRISPR/Cas9 to attack and destroy viral DNA has been known for years.


In 2012, J. Doudna and E. Charpentier repurposed CRISPR/Cas9 so that it can target DNA of highly specific sequences of interest. This particular discovery revolutionized the tools and techniques to approach genome editing, namely the introduction or deletion of desired and known DNA sequences of other cells or living organisms. As a result, scientists can, nowadays, design CRISPR/Cas9 to precisely identify and activate or inactivate genes or sequences that have a specific function. For instance, researchers have engineered CRISPR/Cas9 in order to recognise the DNA of HIV-1, which is the virus that causes AIDS. This approach has been successful in human cells in vitro (namely in the laboratory, “test-tube” experiments) and in animal models.


This and other relevant discoveries suggest a promising future to cure genetic diseases. On the other hand, it can be easily perceived that CRISPR/Cas9 design tool may be catastrophic if it falls into the wrong hands. It has been almost a year now, the first announcement was made (19 November 2018). It was true. The first ever genetically edited babies were born. Lulu and Nana are the two pseudonyms given to the twins born in October 2018 in China. Chinese scientist He Jiankui secretly performed an experiment where he exploited the CRISPR/Cas9 mechanism to delete the gene CCR5 to provide resistance to HIV in the two in vitro fertilized babies. Even though the babies were born healthy, widespread controversy and criticism propagated rapidly around the scientific community, which inevitably shocked the whole world. Following that, researchers and intellectuals around the globe started asking the consequences of such actions.

Obviously, many ethical issues arise that combined with the power of gene editing look, sound and feel scary, especially for laypeople, who do not have the sufficient understanding and background knowledge to grasp complicated topics like this one. Thus, many a question arises that agonizes public opinion. What should we, as individuals and as a society, do then? What are the limits of our knowledge? Who sets the relevant borderline of acceptable and ethical experiments? Is our knowledge our own house of cards …?

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