HEALTH 18th July 2018

How safe is CRISPR-CAS9
Gene Editing?


In June 2012, American and French molecular biologists Emmanuelle Charpentier and Jennifer Doudna published a research paper that rocked the scientific community and made headlines around the world. Their research lifted the veil on one of nature’s most remarkable mechanisms: a tool within the cells of bacteria, that can repair human DNA.

The mechanism, known as CRISPR was hailed as a huge turning point in human medicine, because if the researchers were right, CRISPR had the potential to wipe out every disease known to mankind. But in a report published earlier this week, that notion was challenged.


CRISPR stands for Clustered Regularly Interspaced Short Palindromic Repeats. It represents the DNA sequence found in a group of bugs known for their resilience to toxic environments. In other words, these bugs displayed superior immune systems.

But the key to their immunity was a virus-fighting protein known as CAS9. Researchers like Charpentier and Doudna argue that defunct human genes can be edited by implanting CAS9 into our cells to mimic the CRISPR sequence, and thereby fight genetic mutations which lead to disease. Essentially, CRISPR-CAS9 is said to boost our body’s natural immune system.  However, there is a downside.

Unintended Danger

On Monday, a study published in the journal Nature Biotechnology found that when using CRISPR-CAS 9 to edit the DNA in both mouse and human cells, huge chunks of DNA were unintentionally deleted, rearranged and otherwise mutated.

The findings noted that in 15% of cases, cells lost their entire functionality. For this reason, the study’s author Allan Bradley advocates caution: ‘CRISPR is not as safe as we thought’ and ‘The DNA repair process is not 100 percent foolproof’.

Ultimately, it is hard to predict the consequence of such mutations given there are millions of cells carrying out different roles within the body’s DNA. But the study forces a moment of pause. The risk of unintended havoc is enough to threaten the health of patients who may one day receive CRISPR-CAS9 therapy.

For CRISPR-CAS9 to revolutionize human medicine, further research and specific testing is required before it is used clinically

As always, pushing for health.



Photo Credit: Nils Davey/Investor’s Business Daily