←back to thread

Baby is healed with first personalized gene-editing treatment

(www.nytimes.com)
1162 points jbredeche | 5 comments | 15 May 25 18:06 UTC | HN request time: 0.774s | source
Show context
MrZander ◴[15 May 25 19:30 UTC] No.43998447[source]▶
> To accomplish that feat, the treatment is wrapped in fatty lipid molecules to protect it from degradation in the blood on its way to the liver, where the edit will be made. Inside the lipids are instructions that command the cells to produce an enzyme that edits the gene. They also carry a molecular GPS — CRISPR — which was altered to crawl along a person’s DNA until it finds the exact DNA letter that needs to be changed.

That is one of the most incredible things I have ever read.

replies(20): >>43998602 #>>43999018 #>>43999182 #>>43999228 #>>43999351 #>>43999647 #>>43999883 #>>44000363 #>>44000383 #>>44000524 #>>44000545 #>>44000725 #>>44001330 #>>44002188 #>>44002243 #>>44002289 #>>44002568 #>>44003457 #>>44008340 #>>44011060 #
cryptoegorophy ◴[16 May 25 00:01 UTC] No.44000545[source]▶
How does it know how to gps around? From what I know everything down there is a chemical reaction with some minimal physical motion, but how do you program it to know where to change and what and how.
replies(3): >>44000557 #>>44000649 #>>44001736 #
1. TheJoeMan ◴[16 May 25 00:04 UTC] No.44000557[source]▶
It’s more like a “ctrl+F” for DNA. Hopefully there’s only 1 match (the target site).
replies(2): >>44000942 #>>44003358 #
2. 0x1ceb00da ◴[16 May 25 01:15 UTC] No.44000942[source]▶
So you create a molecule that binds to a certain location in the dna, and then deploy a billion of them?
replies(2): >>44003082 #>>44003821 #
3. rubidium ◴[16 May 25 08:38 UTC] No.44003082[source]▶
More or less, yes.

An interesting part of the study was determining what a clinical dose _should_ be. You need enough to edit enough liver cells. But don’t really want to completely overdo it to limit potentially negative side effects. Seems like they got it right enough here, with the first dose having some effect and the subsequent dose having more.

4. dtpro20 ◴[16 May 25 09:25 UTC] No.44003358[source]▶
Well its more like search and replace, where you cross your fingers that it only replaces the words you are trying replace without impacting the rest of the text in the document.
5. Tuna-Fish ◴[16 May 25 10:52 UTC] No.44003821[source]▶
You need billions to cover multiple cells, you don't need many for a cell.

The counterintuitive part is how fast thermal motion is relative to the size of dna.

In body temperature water, the thermal velocity of water molecules jostling around everything is ~600m/s. The nucleus of a human cell is ~6µm in diameter. That is, your average water molecule bounces around at a speed that makes it move from one end of the nucleus to another roughly 100 million times per second.

Larger molecules move more slowly, but they still zip around fast enough that nothing needs to "seek" to a specific position in a cell to get there, everything will touch everything just from thermal random walk in a very short time. So how biology works is that inside the cell there might be just one messenger, which will have to hit a specific piece of dna just right in order to do anything, but that's still nearly instantaneous from our perspective.