the Cas9 enzyme used in CRISPR

We’re starting to get working gene therapies for single-mutation genetic disorders, and genetically modified cell therapies for attacking cancer.

Some of them use CRISPR-based gene editing, a new technology (that earned Jennifer Doudna and Emmanuelle Charpentier the 2020 Nobel Prize) to “cut” and “paste” a cell's DNA. But so far, the FDA-approved therapies can only edit one gene at a time.

What if we want to edit more genes? Why is that hard, and how close are we to getting there?

How CRISPR Works

CRISPR is based on a DNA-cutting enzyme (the Cas9 nuclease), a synthetic guide RNA (gRNA), and another bit of RNA (tracrRNA) that's complementary to the gRNA. Researchers can design whatever guide RNA sequence they want; the gRNA will stick to the complementary part of the target DNA, the tracrRNA will complex with it, and the nuclease will make a cut [...]

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Outline:

(00:44) How CRISPR Works

(03:38) How Base and Prime Editors Work

(05:41) What About Bridge RNAs?

(06:09) Approaches to Multiplex Gene Editing

(09:39) Who's Doing Multiplex Gene Editing?

(11:46) Ok, What About Highly Polygenic Traits?

The original text contained 6 footnotes which were omitted from this narration.

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First published:
July 16th, 2024

Source:
https://www.lesswrong.com/posts/oSy5vHvwSfnjmC7Tf/multiplex-gene-editing-where-are-we-now