honestly this is the perfect thread for it so sperg about genetics my dude
@Wallace
Right, well... You can change one base here or there if the polymorphism in question is really well-understood, sure. Of course, you need a way to get CRISPR into those cells too. Unless you're doing the experiment at the zygote stage, when a human is still just one cell, good fucking luck. That comment about "less than a thousand dollars in someone's garage" is only going to happen if you're working in something harmless like yeast.
So let's say you can do that, change a few bases in a zygote. You could conceivably fix really simple genetic problems like cystic fibrosis that way. I mean, no one has proven that it
won't work. Ethical and logistical challenges not withstanding. Now you want to move onto something bigger. Say you want a more complex trait, like height. You want your baby to be the next Yao Ming. The problem is that there's not a single, binary gene that determines height. It takes hundreds, all of them working together, in interactions that we still don't fully understand yet. For something even more complex, like intelligence, that number jumps up into the thousands. Can you CRISPR that many genes all at once?
Now let's get really crazy, and try adding some new traits. Assuming we have something from another species that we can use as an analog, like animal fur, how do you introduce it? Where in the genome is it safe to jam in a few thousand bases? Additions like that can effect the expression of many other nearby genes. The number of possible interactions would make the best statisticians cry. We don't even have good tools to interrogate how this could work in a wet-bench setting.
In summary, CRSPR is not the last word in gene therapy. It's a useful tool, to be sure, but we need several more tools and a lot better understanding of how our genome operates before we're realistically ready to modify anything even close to human complexity.