A paper published in a science journal that suggested the gene-editing software CRISPR is dangerous has been retracted. After the study, many researchers accused the authors of the study of careless mistakes, until another study fully discredited their findings.

The future looks brighter for CRISPR at the moment.

Curing Blind Mice

The original study claimed that using CRISPR to cure blind mice caused thousands of unintended effects on other genes. It was published by Nature Methods, and it fully retracted the study last week.

Before the retraction of the study, it already had two previous annotations in it, one was a June 2017 annotation noting that the conclusions found in the paper were subject to criticism and that the editors were looking into it. The other correction came in July 2017 when the editors expressed concern regarding the conclusions of this paper. They said that they would reach out to the authors and critics in order to get to the bottom of it.

In the final correction posted last week, the journal said that it had retracted the study. Editors noted that the study was retracted because the genomic variants observed by the authors in the mice couldn't be attributed to CRISPR-Cas9.

After the study was published, the authors were accused of making mistakes and flaws in the methodology.

Discrediting The Original Study

The original study was proven wrong when another study was published in February 2018. Scientists from the Wellcome Sanger Institute were able to recreate the original study but were not able to find the significant unexpected mutations.

In this study, scientists used more rigorous controls for accuracy. They found that the mice who received the CRISPR treatment didn't have a significant difference in gene mutations compared to those who didn't get the CRISPR treatment.

The original study authors published a paper last week in which they conducted another experiment and used the same methodology from the original paper. They were not able to reproduce the work of the original study.

Authors from the original study wrote in their preprint paper that their original findings were off. They found that using CRISPR didn't lead to numerous, unintended, off-target mutations. This preprint wasn't a retraction of the previous findings until Nature Methods came out against the original study.

Nature Methods concluded that the genetic makeup of the mice's parents was not known and that the control group of mice and the mice that had their DNA edited were not related. This made it impossible for the researchers to tell the genetic differences between the mice.

Previous controversies with CRISPR include the software not working on most humans.