CRISPR is ethical only when it is used on somatic cells
Many scientists and ethicists have voiced concern over genetically editing reproductive and germ cells. This is because the CRISPR edits would then be inheritable to the children of the individual who has been treated with CRISPR. Since we do not know the long-term effects of CRISPR, we should not allow the effects of CRISPR to be passed on to the next generation. Even if just one person who had their reproductive cells edited with CRISPR chose to reproduce, the entire human gene pool could be radically changed. That change may not be for the better, so it is unethical to allow CRISPR changes to be inherited.
In the human body, there are somatic, germ, and reproductive cells. Reproductive cells are sperm cells and egg cells, while germ cells are simply cells that go on to become reproductive cells. Editing reproductive cells results in an inheritable change. If a person who had CRISPR used on their reproductive/germ cells had a child, that child would inherit the CRISPR modifications. Using CRISPR on embryos is another kind of genetic modification of reproductive cells. On the other hand, somatic cells are any other cell that is not a reproductive or germ cell in the human body. Thus, by definition, somatic cells are not involved in the reproductive system and are not passed on in any way to a human’s children. Many ethicists and scientists have taken the stance that CRISPR should only be used on somatic cells, so that any genetic modifications are not inheritable. This is because we cannot predict how CRISPR may affect individuals over time. Some studies have already shown that CRISPR could make unwanted changes to the human genome when using it to correct genetic conditions. The issue is that the technology is not entirely precise. When targeting a certain part of the genome to cut, CRISPR can sometimes cut out parts of the genome that are next to the targeted area. Since CRISPR could result in unwanted changes, we should not allow the effects of CRISPR to be inheritable. Even if only one person with CRISPR-edited DNA reproduced, the human gene pool would be massively impacted, as this would add entirely new possibilities.
If we were to track individuals who have had their reproductive/germ cells edited, then we would not need to worry about the human gene pool being massively changed. We would simply need to keep a record of every individual who has their reproductive/germ cells edited and keep a record of any children that that individual has. So then, if we learned that the genetic edits could result in significant long-term consequences, we could inform everyone who has had that done to them and hopefully convince them not to reproduce. If we kept accurate, updated records of anyone who has genetically altered reproductive/germ cells, then we could avoid ethical concerns attached to germline editing.