Any mutations that CRISPR might make—intentional or not—would almost certainly pale in comparison to the genetic storm that rages inside each of us from birth to death. As one writer put it, “Genetic editing would be a droplet in the maelstrom of naturally churning genomes.” If CRISPR could eliminate a disease-causing mutation in the embryo with high certainty and only a slight risk of introducing a second off-target mutation elsewhere, the potential payoffs might well outweigh the dangers.
