7 min read
Casgevy Doesn’t Fix the Sickle Cell Mutation
It goes around it. That’s why it works.
Sickle cell disease is a single-letter typo in DNA. CRISPR can now edit DNA with precision. You'd think the fix is obvious. It's not. Casgevy uses CRISPR to reactivate fetal hemoglobin instead of correcting the mutation directly — because the indirect approach is proving safer and more effective.