When the gene-editing tool CRISPR was introduced, it was hailed as the cure to all diseases including cancer. Recently, however, scientists discovered that there is a fatal flaw to the method. A flaw that can have dangerous effects if left unaddressed.

The CRISPR-Cas9 gene editing tool has been touted to have the power to cure all genetic diseases, blindness, and cancer by adding, repairing, or deleting specific parts of the genome.

A team of researchers from the United States also used the method to restore sight to blind mice. The experiment was successful but the scientists noticed something else that caused alarm - it caused unintended mutations. Specifically, they found more than 1,500 small mutations and more than a hundred larger insertions and deletions in two of the sections of the mice.

Professor Stephen Tsang of Columbia University said that the scientific community should be aware of the potential hazards of off-target mutations if scientists will not use whole genome sequencing, which is necessary if testing live animals. He added that even the tiniest change in a single nucleotide can have great impact.

With that in consideration, Tsang encouraged other researchers who are using the CRISPR-Cas9 gene editing tool to use whole genome sequencing to find any off-target as well as important mutations.

Compared to the computer algorithm they used, he said that genome sequencing is important because it allows scientists to look at different edited versions of the genome and find the safest and most effective editing. A computer algorithm, on the other hand, is only effective when studying tissues in the laboratory.

Even though they issued the warning, researchers said that they are aware of the potential risks of CRISPR-Cas9 since it is considered a new kind of therapy. However, they believe that it still holds a lot of promise in fighting diseases.