If they're going to all that effort to make allele-specific guides why not just cut out the centromere and eliminate the chromosome entirely? This seems like an overly complicated solution.
My understanding is that crispr is less like a scalpel and more like a chainsaw. Great care just be taken to avoid introducing cancer causing mutations.
I wouldn't characterize it like that. It makes mistakes. It's a scalpel in shaky hands. When it works correctly it is very precise but just not 100% reliably.
in vitro there are various techniques where you use crispr on a cell line and then purify it by killing off the cells with errors and only then implant them
in vivo... well there are errors and among other effects are potential cancer
I wondered the same thing and according to Gemini a chromosome is massive vs a few genes. Cutting it out with crispr is possible, but it's too big of a change and would lead to cell death rendering whatever change either useless or kills the host given the possible stage this treatment could be delivered at.
Since the presence of that chromosome causes problems in an organism that functions normally with just two of these chromosomes, the change is actually not that big. And the therapy might also not be intended for adults or even children - most of the developmental impediments have already happened at that stage, and neither cutting out the extra chromosome or silencing it will fix this up.
