Here, we report the first step towards an autologous HSPC transplantation using the CRISPR/Cas9 system for FRDA. We first identified a pair of crRNAs that efficiently removes the GAA expansions in human FRDA lymphoblasts restoring non-pathologic level of frataxin expression and normalizing mitochondrial activity. We also optimized the gene editing approach in HSPCs isolated from healthy and FRDA patients’ peripheral blood, and demonstrated normal hematopoiesis of gene-edited cells in vitro and in vivo. The procedure did not induce cellular toxic effect or major off-target events, but a p53-mediated cell proliferation delay was observed in the gene-edited cells. This study provides the foundation for the clinical translation of autologous transplantation of gene-corrected HSPCs for FRDA.
CRISPR/Cas9 gene editing of hematopoietic stem cells from patients with Friedreich’s ataxia
