Will Crispr save us all?
We’ve all heard of it in the news lately, in the last year or two not a month goes by that we don’t have something pop into the news with a headline of “scientists at XXX find a cure to YYY with Crispr” If you read the news the cure is that they've devised a new way to target a gene that causes the ailment, and are fixing it via crispr, and that its in trials with rats and maybe a couple of humans.
The lack of excitement in my tone isn’t that this isn’t exciting territory, it certainly is, its that the news is presented as more than what we have. To fully understand the situation one has to know what crispr does, and what one can cure with what crispr does.
Ailments that are caused by a genetic mutation, or a particular gene (or collection of genes in most cases) that cause your body to produce a faulty protein. This protein can then either not work as its supposed to (such as in lactose intolerence) or it can work too well (as in most autoimmune desies). In most cases we have a range of activity of a protein that we can work well with, but once it goes out of this range we start to have some problems. Think of it as the oil in your car, within a certain range you are fine, if there isnt enough it starts to go badly, and ultimately breakdown.
CRISPR, is a technique that takes a bit of a gene and replaces it with another bit. The way you cut the bit of genetic material out of the rest of the DNA is using CAS9 a protein that acts as a set of scizors so that they cut at a particular place in the genome. The gene then repairs itself with the new dna.
So this seems like it can let us fix anything. And it does, potentially. There are a few issues, for starters it takes some work to cut at the appropriate place. To put a comparison we have a country worth of roads as our DNA, and we are replacing a block. And if we replace something else, or a bit more it can have catastrofic effects, so its not something that we can just cook up in an evening in the lab.
When we do figure out how to make it work for a particular protein we test it and work on making sure it is unique to that gene. Once that is sorted, and we find a way to deliver the mix to the cells we want to alter (because again, this is powerful stuff, we can alter most all of a humans cells, but often that may not be the way we want to go), we start trials.
Again, if we’re at trials, why aren’t I more excited?
I am, really, but this is also a somber activity, we are modifying replicating DNA in a reproductive human. We are at the very core touching how future generations will be. And while there is nothing wrong with removing a mutation that causes cancers and nothing else, or leads to severe learning disabilities, are we only touching that?
This is an area that scientists themselves are debating with, how much do we edit, how much is allowed into the gene pool, are we sure we aren’t inducing long term problems?