Jack of All Trades

Today the US Food and Drug Administration (FDA) approved two gene-based treatments for sickle cell disease, Casgevy and Lyfgenia, a genetic disease that can cause extreme pain and reduces average life expectancy to 53 years. Prior to these approvals, the only cure for sickle cell disease was bone marrow transplant but only about a fifth of patients are able to find donor.

One of the treatments, Casgevy, is the first-ever approved gene therapy to use the gene-editing technique, Clustered Regularly Interspaced Short Palindromic Repeats Crispr-Cas9  commonly referred to as “CRISPR”  (pronounced “crisper”). The one-time therapy changes the DNA in a patient’s blood cells and  eliminates the symptoms of sickle cell disease for life.

Search and Replace 
CRISPR technology fixes a disease-causing error in an individual’s DNA by replacing it with the correct code. It’s analogous to how a typo is corrected in a Microsoft Word document.

Let’s say you are proofreading a document, and read the sentence:

A jack of small trades is master of none.

You quickly realize that the word “small” is an error. One possible fix is to simply delete “small”:

A jack of trades is master of none.

Nope – that does not does not convey the intended meaning.

Another possible fix is to add the word  “all”

A jack of all small trades is a master of none.

No – again the correction results in the sentence no longer conveying the intended thought.

The solution? Use the Search and Replace tool to change  “small” to  “all” in this sentence and in all other occurrences in the document!

CRISPR edits genes in a similar manner, finding the error and replacing it with the correct genetic code!

From Small to All
Sickle cell disease affects more than 100,000 Americans, the majority of whom are Black. However, sickle cell disease also affects people from Hispanic, southern European, Middle Eastern and Asian Indian backgrounds. About 20,000 people in the US are thought to have a severe enough form of the disease to potentially qualify for the newly approved gene therapies.

Although the number of people who may benefit from today’s approval may seem a bit small, the FDA approval of the first-ever CRISPR gene therapy is huge.  Experts believe that sickle cell disease is the first of many other diseases that will be effectively treated or cured using CRISPR technology. Check out Breaking New Ground for more on the new gene therapies for sickle cell disease.

Happy Reading!

Suzanne Daniels