Off-target editing (edits outside the target site)

This term refers to a situation in genetic editing where changes are made to the DNA or RNA that the researcher did not intend to make.

Genetic editing can be understood by comparing it to using a word processor like Microsoft Word or Google Docs. Just as you can search for and replace a specific word in a document, genetic editing involves using sophisticated tools to search for a specific sequence in the DNA bases and replace it with another sequence. This can correct mutations, for example.

However, unlike a word processor that replaces only the word you chose, genetic editing of DNA sequences can result in additional, unintended changes, such as accidentally deleting a segment at the wrong part of the DNA sequence. Such changes, which were not the researcher's objective, are referred to as "off-target editing."

Off-target edits can disrupt other genes, causing irreversible damage and potentially leading to mutations that increase the risk of various diseases, including cancer. This is why scientists are developing tools to prevent such edits, and to improve the overall efficiency and accuracy of genetic editing.