Scientists have successfully performed CRISPR gene editing in a live human body for the first time ever

CRISPR-Cas9 is the cutting-edge genomic technology that essentially lets you target exact sequences in DNA and then cut into them like a knife and insert or remove a gene. You may remember it from that Chinese scientist who successfully (but controversially) implanted gene-edited embryos into a woman who then gave birth to live lab babies. More often, it's used to create things like malaria-resistant mosquitoes or mushrooms that don't brown as fast.

But it does have a lot of practical medical potential, too. It's already been used to remove HIV from a patient's genome. And now, after CRISPRing out a blindness-causing gene from mice, scientists have now successfully scaled-up this procedure to work in a live human body. From NPR:

In this new experiment, doctors at the Casey Eye Institute in Portland, Ore., injected (into the eye of a patient who is nearly blind from a condition called Leber congenital amaurosis) microscopic droplets carrying a harmless virus that had been engineered to deliver the instructions to manufacture the CRISPR gene-editing machinery.

[…]

The goal is that once the virus carrying the CRISPR instructions has been infused into the eye, the gene-editing tool will slice out the genetic defect that caused the blindness. That would, the researchers hope, restore production of a crucial protein and prevent the death of cells in the retina, as well as revive other cells — enabling patients to regain at least some vision.

[…]

The procedure, which takes about an hour to perform, involves making tiny incisions that enable access to the back of the eye.

Read the rest

ENCODE, the media, and what we really know about the human genome

If you've read anything in the past week about ENCODE—a group of laboratories that recently published their latest work on the human genome—then you need to read John Timmer's excellent piece over at Ars Technica.

What ENCODE has actually done, and why it matters, has been widely misrepresented in the mainstream press—largely because of misleading press releases put out by ENCODE, itself. Timmer sets the record straight. It's a long read, but a fascinating one. Highly recommended.

This week, the ENCODE project released the results of its latest attempt to catalog all the activities associated with the human genome. Although we've had the sequence of bases that comprise the genome for over a decade, there were still many questions about what a lot of those bases do when inside a cell. ENCODE is a large consortium of labs dedicated to helping sort that out by identifying everything they can about the genome: what proteins stick to it and where, which pieces interact, what bases pick up chemical modifications, and so on. What the studies can't generally do, however, is figure out the biological consequences of these activities, which will require additional work.

Yet the third sentence of the lead ENCODE paper contains an eye-catching figure that ended up being reported widely: "These data enabled us to assign biochemical functions for 80 percent of the genome." Unfortunately, the significance of that statement hinged on a much less widely reported item: the definition of "biochemical function" used by the authors.

This was more than a matter of semantics.

Read the rest