Published today (Tues Feb 25th, 2020) in Independent Science News: Researchers Are Substantially Undercounting Gene-Editing Errors, Concludes a New Paper, written by Jonathan Latham, PhD.
Synopsis: New research on mice has found that complex and aberrant DNA insertions are common results of gene-editing. The findings applied across multiple experiments on independent edits from different genome locations. Even more notable, however, these complex genetic rearrangements at the edit site were only rarely detected by standard analytical methods. The authors called this finding “disturbing”. The research suggests, therefore, that not only is gene-editing more error-prone than thought, but that many researchers are falsely claiming to have obtained precise edits.
Read the full article at:

There is now a substantial collection of scientific papers describing various forms of commonplace gene-editing errors. GM Watch has compiled a reference list of these papers (each with a summary of their import) here:

The imprecision of gene-editing has important implications for biosafety. These collected papers indicate that the media, biotechnologists, policy makers and regulators have underestimated the risks arising from gene-edited GMOs created for use in agriculture, as well as risks arising from gene-editing’s proposed environmental and clinical uses.