Off target effects from CRISPR is not new. The method leverages DNA repair mechanisms in the cell to do the recombination. All errors involved in those DNA repair mechanisms (there are distinct ones) would apply here。
The original bacteria CRISPR can only cut off pre-defined sequences, but the artificial gene tech CRISPR can add and edit as well. I'm wondering if the later two modes are the sources of the genome damage.
I was under the impression that addition and editing capability were essentially done by injecting the sequence that is desired and performing the cut. Then you simply rely on the repair mechanisms to have a chance to put the new segment in instead of the old segment. Is that not the case?