Zapping bad genes

I read this afternoon, at references 1 and 2, about editing out bad genes in our body to deal with this or that gene problem - that is to say a gene that either directly causes or increases the risk of some disorder or other. So one might want to change the bad value of the gene to a good value or one might want to simply disable the gene, to stop it working at all. Put another way, one wants either to repair a good pathway which has gone wrong, or to disrupt a bad pathway.

My understanding, such as it is, that finding a suitable gene edit for any given disorder is hard. And so far, not all that many edits for not all that many disorders have been found. So the first trick is to find a gene-disorder pair which looks promising. Which has to include economic viability: there has to be enough of the disorder about and it has to be serious enough to justify all the expense.

The second trick, Nobel prize worthy, is to develop something (say agent A) which you can inject into a cell to make the required change. 

The third trick is to develop a delivery vehicle to get agent A to all the cells concerned, in the human concerned, or at least to enough of them to make a difference. Presumably, millions, if not billions, of them. Given that targeting is unlikely to be that precise, it must not matter if cells not on the pathway involved get edited too. In the present case, all the cells concerned are conveniently concentrated in the liver.

It seems that what you do is prepare a suitable liquid vehicle for agent A, which in the present case takes the form of a nanoparticle. This liquid is then introduced in the the extracellular spaces involved, perhaps by drinking it, perhaps by direct injection, perhaps by injection into the bloodstream. This gets agent A close enough to a good proportion of the target cells. It then binds to or jumps into those cells and does its stuff. And should those edited cells replicate, the replicas will carry the edit forward.

Which all sounds very promising - but there is lots of work to do yet and plenty for the quality control and ethics people to get their teeth into.

PS: it seems that for cultural reasons, it is easier to get people to agree to this sort of thing in China than it is here in the west, where we are deeply suspicious of people who want to meddle with our genes. Just think of those people who got acquitted by the jury of criminal damage, after they had trashed thousands of pounds worth of some genetically modified food crop, somewhere in Norfolk as I recall.

References

Reference 1: Edits to a cholesterol gene could stop the biggest killer on earth: In a first, a patient in New Zealand has undergone gene-editing to lower their cholesterol. It could be the beginning of new era in disease prevention - Antonio Regalado, MIT Technology Review - 2022.

Reference 2: https://www.vervetx.com/. Accessible to the amateur and a good supplement to reference 1. The source of the snap above.

Reference 3: https://en.wikipedia.org/wiki/CRISPR_gene_editing. No doubt good stuff, but not much help to me.