Fecha de publicación: -- Fuente: WIPO "tomato" The CRISPR-Cas9 system has revolutionized our ability to precisely modify the genome and has impelled gene editing into clinical applications. Comprehensive analysis of gene editing products at the targeted cut-site revealed a complex spectrum of outcomes. ON-target genotoxicity is underestimated with standard PCR-based methods and necessitates appropriate and sensitive detection methods. Here, the inventors developed two complementary Fluorescence-Assisted Megabase-scale Rearrangements Detection (FAMReD) systems that enable detection, quantification, and cell sorting of edited cells with megabase-scale loss of heterozygosity (LOH). They revealed rare complex chromosomal rearrangements caused by Cas9-nuclease and showed that LOH frequency depends on cell division rate during editing and p53 status. Cell cycle arrest during editing suppressed the appearance of LOH without compro-2024/235844 mising editing. These data were confirmed in human stem/progenitor cells, suggesting that clinical trials should consider p53 status and cell proliferation rate during editing to limit this risk and design safer protocols.