Narrative review of CRISPR-Cas9 and Fanzor gene therapies for sickle cell diseaseNew CRISPR gene therapies for sickle cell disease face lingering technology limits

Advancements in genome editing have established a new frontier for the treatment of various genetic diseases, including sickle cell disease (SCD). SCD, the most prevalent monogenic blood disorder, causes severe pain, organ damage, and reduced life expectancy. The recent clinical approval of clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9-based gene therapies for severe sickle cell anemia marks a significant milestone in treating genetic diseases. Despite these breakthroughs, limitations in CRISPR technology persist, requiring further innovation. Alternative approaches, such as the Fanzor (Fz) system, are being developed to complement CRISPR’s capabilities. Unlike CRISPR, which is typically encoded within prokaryotic organisms, Fz is encoded in the eukaryotic genome, offering a universal RNA-guided mechanism applicable across all life kingdoms. Fz’s eukaryotic origin may facilitate more efficient delivery across diverse cell types and tissues, enhancing its therapeutic potential. Here, we will review the current successes and limitations of the CRISPR technology in editing mutation associated with SCD. Additionally, we will explore the potential role of Fz as a genome-editing tool for SCD, a field where its application has not yet been studied.