Fixing Faulty Genes On the Cheap 105
An anonymous reader sends an article about CRISPR, a system for modifying genes and moving them from cell to cell. It's notable because the cost to do so is dropping to the point where it's becoming viable to use on a patient-by-patient basis.
CRISPR is one of those interesting inventions that comes, not from scientists explicitly trying to cure a disease, but from researchers trying to understand something fundamental about nature. Jennifer Doudna's research at the University of California, Berkeley has focused on how bacteria fight the flu. It turns out bacteria don't like getting flu any more than the rest of us do. Doudna says the way bacteria fight off a flu virus gave her and her colleagues an idea. Bacteria have special enzymes that can cut open the DNA of an invading virus and make a change in the DNA at the site of the cut — essentially killing the virus. Doudna and other scientists figured out how this defense system works in bacteria; that was interesting all by itself. But then they realized that they could modify these enzymes to recognize any DNA sequence, not just the DNA sequence of viruses that infect bacteria.
Even if it's American expensive (Score:2, Informative)
It could be worth it. This could be huge. Besides sickle cell, there's cystic fibrosis and a bunch of others. Not to mention high vulnerability to cancer caused by faulty genes. Angelina Jolie could still have her breasts. I could stop taking medication for gout.
Confused about how this works (Score:5, Informative)
From the Wikipedia article, it seems like CRISPR works by injecting a strand of "neutral" genetic material into a genome and cause genes to not be transcribed - so you can "turn off" an improperly expressed gene, but can't actually replace it with a normal one. The NPR article, however, has people mentioning the idea of replacing improperly expressed genes with normal ones.
From what I understand, the difference between the two is that if Wikipedia is correct, CRISPR would only be useful in humans (once they get it to be accurate) to cure diseases that arise from a gene being expressed when it shouldn't be, for things like sickle cell or Huntington's. However, if NPR is correct, CRISPR can also cure diseases that arise from a gene not being expressed when it should, such as hemophilia.
Which one of these is correct? What is CRISPR actually good for?
Re:How long before... (Score:3, Informative)
OK, smartass, what is the evolutionary advantage for stupidity?
I suggest you ask evolutionary biologists. Specifically, go ask that group of evolutionary biologists standing over there lamenting their inability to connect with females, who somehow prefer muscularly ripped albeit less cranially endowed surfer dudes.
Am I kidding? I'm not sure.
Re:Confused about how this works (Score:5, Informative)
CRISPR is a tool that allows you to cut the DNA in two disjoint pieces at a specific point (specification of this point is a parameter of a particular CRISPR instance). What happens then depends on your setup; bacteria will just insert some junk at that break point, or you can pack your custom DNA sequences along the CRISPRs and they will be spliced in, connecting to each of the two disjoint pieces by one end. Thanks to this, at that specific point, you can disable a gene or modify or add an extra sequence.
We had tools to do this before - restriction enzymes or TALENs. They weren't really usable for therapeutic purposes, though, due to much less reliable targetting, more laborous engineering (parametrizing your instance for a specific sequence) and low effectivity (the break happens only in a a few percents of cases). CRISPRs are easily parametrized, can be precisely taretted, and have effectivity in tens of percents (in general; can vary organism by organism). It's still a work in progress, but looks pretty promising!
Re:How long before... (Score:2, Informative)
OK, smartass, what is the evolutionary advantage for stupidity?
A complex brain uses energy that could be used elsewhere to propagate the species. Humans are extreme K-strategists [wikipedia.org], which make few babies but put more effort into raising them. So-called "lower" animals may be r-strategists, which make lots of babies in hopes that some survive.