“The pain was like being struck by lightning and hit by a freight train all at once,” Victoria Gray said. The new scientist in 2023. “Everything is different for me now.”
Gray used to have severe episodes of sickle cell disease, but in 2019 she was effectively cured by a revolutionary technique that makes it possible to make changes to specific pieces of our DNA: CRISPR gene editing. In 2023, this experimental treatment became the first approved CRISPR therapy.
There are hundreds of clinical trials of CRISPR-based treatments is now underwayand that’s just the beginning. CRISPR could help treat all kinds of diseases, not just genetic conditions. For example, a single dose of CRISPR could reduce the risk of heart attacks and strokes by permanently lowering cholesterol levels.
And while it’s not yet safe enough to try, it seems likely that in the future CRISPR will be routinely used to alter our children’s genomes to reduce the risk of common diseases.
CRISPR is also beginning to transform agriculture by making it much easier to develop crops and livestock that are disease-resistant, adapted to warmer conditions, or more digestible.
Given all this, there is no doubt that CRISPR is one of the best ideas of the 21st century. Its power lies in its ability to correct “spelling errors” in DNA. There are two parts to this: first, you have to get your gene-editing tool to the right place in the genome, like moving your cursor to the right place in a long computer document. Next, you make the change.
Microbes use this mechanism in their fight against other microbes, and before 2012 biologists discovered many natural gene-editing proteins. However, each targeted only one site or sequence in the genome. To edit a different site, the only option was to reengineer the part of the protein that binds to DNA to target a different sequence, a laborious process that took years.
But it turns out that bacteria have evolved a large family of gene-editing proteins that don’t bind directly to DNA. Instead, they bind to a piece of RNA—a cousin of DNA—and look for sequences that match the RNA. And making RNA takes days, not years.
In 2012, Jennifer Doudna at the University of California at Berkeley and her colleagues Emmanuelle Charpentier at the Max Planck Institute for Infectious Biology in Berlin showed how one of these gene-editing proteins, called CRISPR Cas9, could designed to target any desired sequence by adding the correct form of “guide RNA”.
There are now thousands of CRISPR variants used for many purposes, but they all rely on targeting with a guide RNA. It is a world-changing technology for which Doudna and Charpentier won the 2020 Nobel Prize.
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