@NathanG - I don’t think that the scenario you’ve described stirs any controversy. It’s run of the mill, clinical molecular genetics and I believe that everyone is on board with that.
What stirs controversy is cloning, and in that regard, the passions run very high on either side. Do we have the right to create human clones? If we go down this path, will it lead down a slippery slope where we are attempting to create perfect humans and eradicate people with “imperfections,” as the Nazis did?
I am not saying that I subscribe to these beliefs; I am just saying that this is what’s being said. I do believe we need to have ethical discussions about these issues, although personally I am in favor of all forms of genetic engineering so long as it advances science.