Nature Methods has retracted a paper that argued that the CRISPR/Cas9 gene-editing technique led to a number of unintended edits, Retraction Watch reports.
The paper from Stanford University's Vinit Mahajan and colleagues described how they sequenced the genomes of two mice that had undergone CRISPR-based editing to repair the retina pigmentosa gene and a control mouse to find additional sites affected by the editing machinery. The paper led the stocks of CRISPR-based companies like Editas Medicine, CRISPR Therapeutics, and Intellia Therapeutics to fall.
However, questions about the study quickly arose. Both Intellia Therapeutics and Editas Medicine sent letters to Nature Medicine criticizing the paper and saying that its data don't support the conclusion it makes. Other researchers also said that the researchers could be attributing normal variation to the effects of the CRISPR tool.
Retraction Watch reports the researchers now have a preprint at BioRxiv that concedes that CRISPR gene editing might not have introduced the differences they saw. Additionally, Nature Methods has retracted the paper as "the genomic variants observed by the authors in two CRISPR-treated mice cannot be conclusively attributed to CRISPR–Cas9," according to the retraction notice.
Author Stephen Tsang from Columbia University tells Retraction Watch that "we ultimately agree with the retraction given that more WGS should be performed to preserve scientific rigor. It is only then that any definite conclusions can be made."