Gene Editing in Live Mice Cures Rare Liver DiseaseScientists at MIT have successfully used the CRISPR method to replace faulty genes in live mice, curing a rare liver disease. This type of genetic modification has been done in the past, but only in vitro [think petri dish]. Making this a monumental step forward for curing people who are suffering from genetic disease.
A Intro to Genetic Editing
The big questions of course are probably, why is this so hard and what the hell is CRISPR? So to answer those questions here is just a semi-short rundown on genetic editing.
Your genome is made up of 23 pairs chromosomes, a chromosome is a package of genes. For simplicities sake think of it as an envelope.
Inside that envelope of course is words, or base pairs [single letters of the entire message]. Your DNA is hundreds of thousands of single letters, to put into perspective how long your DNA “letter” is, the bible, which is a fairly large book is made up of roughly 3,566,480 letters. In contrast your DNA is comprised of 3,200,000,000 letters [on just one side of your genome, and there is two sides].
Now the english alphabet is 26 letters, your biological alphabet is just 4 letters, A, G, T, and C
So with 3,200,000,000 making up “you” and only 23 pairs of “envelopes” to sort through, finding the gene [a gene is just a certain length of the DNA code, just as a word is made up of a certain amount of letters, so imagine for this example a gene is just a word] that is causing the problem is hard. It would be like flipping through a bible but the words have no spaces and having to pick out the misspelled word.
Once it is found, figuring out a way to change it, without changing every other instance of the same “misspelling”, which in other parts of the text might not be a misprint at all, after all with only 4 letters, you are going to have quite a bit of the same “words” in the text and only one you want to edit, it can be a challenge.
Combine that, with the fact that there is more than one cell that needs to be changed and you are left with one hell of a technical problem that is a lot harder to fix. That is where CRISPR comes in.
CRISPER is, in simplest terms, the same method that viruses use to insert malicious code into DNA. The method can make a single cut in the genome [since there are two sides] or it can cut both sides, it can take out code [delete letters or words] or add them [insert letters or words] and this method is accurate enough to pick out single genes in the genome [single words] correctly.
Right now, the team had to use a high pressure injection to deliver the CRISPR components, in the future safer and more efficient ways to insert the components into the genome will be researched and used.
While human trials are still going to be years away, this is an amazing advancement and it is exciting to see what the future will hold.
For an in depth description, you can read more about CRISPR here.