Altering DNA can be done in two ways and for two reasons, giving four scenarios with varying ethical considerations. The ways are somatic and germline and the reasons are therapeutic and enhancement.

Somatic cells are cells which aren’t involved in reproduction. Changes to somatic cells don’t get passed on to children. Changes to germline cells do cause those changes to be inherited. A therapeutic reason is to eliminate a disease. An enhancement would be something like making someone taller or giving them blue eyes.

Altering somatic cells for therapeutic reasons isn’t any different than other medicine. Altering germline cells for enhancement reasons isn’t any different than eugenics.

Altering somatic cells for enhancement reasons and altering germline cells for therapeutic reasons are where the debates tend to be. While having the procedures done can be considered a huge benefit, it can be argued that they could also create biases against people who don’t have them performed, which is essentially the plot of the sci-fi movie GATACA.