Transcriptome-wide deamination analysis

Adenosine base editing to recreate the HPFH mutations is a promising approach to induce HbF. To measure Cas-independent off-target editing of mRNA, we electroporated CD34+ cells from three different donors with RNP consisting of ABE7.10 or ABE8e complexed with the -globin −175 A>G targeting sgRNA. Six days later, this was followed by high-depth RNA-seq. The rates of A-to-I conversion were similar in edited and unedited control cells, which is consistent with previous reports that off-target RNA editing was not detected after high-level adenine base editing of HUDEP2 cells or HSPCs. Total RNA-seq were performed in untreated, mock electroporated and ABE7.10 and ABE8e RNP complexed with the g-globin -175-targeting sgRNA in CD34+ HSPCs.