Sharon Begley at StatNews.com reported on an American Society of Hematology’s workshop on genome-editing held last week in Washington, where researchers met to discuss the quickly advancing world of genome-editing.
Although most members of the 150 person panel were positive about the future of gene-editing, Begley wrote that Dr. J. Keith Joung of Massachusetts General Hospital discussed, “an emerging concern that some enthusiastic CRISPR-ers are ignoring growing evidence that CRISPR might inadvertently alter regions of the genome other than the intended ones.”
From the StatNews.com article:
One reason for concern about off-target effects is that genome-editing might disable a tumor-suppressor gene or activate a cancer-causing one. It might also allow pieces of two different chromosomes to get together, a phenomenon called translocation, which is the cause of chronic myeloid leukemia, among other problems.
Many researchers, including those planning clinical trials, are using web-based algorithms to predict which regions of the genome might get accidentally CRISPR’d. They include the scientists whose proposal to use CRISPR in patients was the first to be approved by an NIH committee. When scientists assure regulators that they looked for off-target effects in CRISPR’d cells growing in lab dishes, what they usually mean is that they looked for CRISPR’ing of genes that the algorithms flagged.
As a result, off-target effects might be occurring but, because scientists are doing the equivalent of the drunk searching for their lost keys only under the lamppost, they’re not being found.