Cao, A. & Galanello, R. Beta-thalassemia. Genet. Med. 12, 61–76 (2010).
Origa, R. Beta-thalassemia. Genet. Med. 19, 609–619 (2017).
Taher, A. T., Musallam, K. M. & Cappellini, M. D. β-Thalassemias. N. Engl. J. Med. 384, 727–743 (2021).
Hardouin, G., Miccio, A. & Brusson, M. Gene therapy for β-thalassemia: current and future options. Trends Mol. Med. https://doi.org/10.1016/j.molmed.2024.12.001 (2025).
Wang, L. et al. Eliminating base-editor-induced genome-wide and transcriptome-wide off-target mutations. Nat. Cell Biol. 23, 552–563 (2021).
Han, W. et al. Design and application of the transformer base editor in mammalian cells and mice. Nat. Protoc. 18, 3194–3228 (2023).
Han, W. et al. Base editing of the HBG promoter induces potent fetal hemoglobin expression with no detectable off-target mutations in human HSCs. Cell Stem Cell 30, 1624–1639 (2023).
Galanello, R. & Origa, R. Beta-thalassemia. Orphanet J. Rare Dis. 5, 11 (2010).
Thein, S. L. The molecular basis of β-thalassemia. Cold Spring Harb. Perspect. Med. 3, a011700 (2013).
Cavazzana-Calvo, M. et al. Transfusion independence and HMGA2 activation after gene therapy of human β-thalassaemia. Nature 467, 318–322 (2010).
Thompson, A. A. et al. Gene therapy in patients with transfusion-dependent β-thalassemia. N. Engl. J. Med. 378, 1479–1493 (2018).
Locatelli, F. et al. Betibeglogene autotemcel gene therapy for non-β0/β0 genotype β-thalassemia. N. Engl. J. Med. 386, 415–427 (2022).
Li, S. et al. Modified lentiviral globin gene therapy for pediatric β0/β0 transfusion-dependent β-thalassemia: a single-center, single-arm pilot trial. Cell Stem Cell 31, 961–973 (2024).
Kwiatkowski, J. L. et al. Betibeglogene autotemcel gene therapy in patients with transfusion-dependent, severe genotype β-thalassaemia (HGB-212): a non-randomised, multicentre, single-arm, open-label, single-dose, phase 3 trial. Lancet 404, 2175–2186 (2024).
Bauer, D. E. et al. An erythroid enhancer of BCL11A subject to genetic variation determines fetal hemoglobin level. Science 342, 253–257 (2013).
Canver, M. C. et al. BCL11A enhancer dissection by Cas9-mediated in situ saturating mutagenesis. Nature 527, 192–197 (2015).
Traxler, E. A. et al. A genome-editing strategy to treat β-hemoglobinopathies that recapitulates a mutation associated with a benign genetic condition. Nat. Med. 22, 987–990 (2016).
Musallam, K. M. et al. Fetal hemoglobin levels and morbidity in untransfused patients with β-thalassemia intermedia. Blood 119, 364–367 (2012).
Bauer, D. E. & Orkin, S. H. Hemoglobin switching’s surprise: the versatile transcription factor BCL11A is a master repressor of fetal hemoglobin. Curr. Opin. Genet. Dev. 33, 62–70 (2015).
Canver, M. C. & Orkin, S. H. Customizing the genome as therapy for the β-hemoglobinopathies. Blood 127, 2536–2545 (2016).
Wienert, B., Martyn, G. E., Funnell, A. P. W., Quinlan, K. G. R. & Crossley, M. Wake-up sleepy gene: reactivating fetal globin for β-hemoglobinopathies. Trends Genet. 34, 927–940 (2018).
Sankaran, V. G. et al. Human fetal hemoglobin expression is regulated by the developmental stage-specific repressor BCL11A. Science 322, 1839–1842 (2008).
Wu, Y. et al. Highly efficient therapeutic gene editing of human hematopoietic stem cells. Nat. Med. 25, 776–783 (2019).
Zeng, J. et al. Therapeutic base editing of human hematopoietic stem cells. Nat. Med. 26, 535–541 (2020).
Frangoul, H. et al. CRISPR–Cas9 gene editing for sickle cell disease and β-thalassemia. N. Engl. J. Med. 384, 252–260 (2021).
Fu, B. et al. CRISPR–Cas9-mediated gene editing of the BCL11A enhancer for pediatric β0/β0 transfusion-dependent β-thalassemia. Nat. Med. 28, 1573–1580 (2022).
Locatelli, F. et al. Exagamglogene autotemcel for transfusion-dependent β-thalassemia. N. Engl. J. Med. 390, 1663–1676 (2024).
Haapaniemi, E., Botla, S., Persson, J., Schmierer, B. & Taipale, J. CRISPR–Cas9 genome editing induces a p53-mediated DNA damage response. Nat. Med. 24, 927–930 (2018).
Schiroli, G. et al. Precise gene editing preserves hematopoietic stem cell function following transient p53-mediated DNA damage response. Cell Stem Cell 24, 551–565 (2019).
Kosicki, M., Tomberg, K. & Bradley, A. Repair of double-strand breaks induced by CRISPR–Cas9 leads to large deletions and complex rearrangements. Nat. Biotechnol. 36, 765–771 (2018).
Cullot, G. et al. CRISPR–Cas9 genome editing induces megabase-scale chromosomal truncations. Nat. Commun. 10, 1136 (2019).
Tsuchida, C. A. et al. Mitigation of chromosome loss in clinical CRISPR–Cas9-engineered T cells. Cell 186, 4567–4582 (2023).
Komor, A. C., Kim, Y. B., Packer, M. S., Zuris, J. A. & Liu, D. R. Programmable editing of a target base in genomic DNA without double-stranded DNA cleavage. Nature 533, 420–424 (2016).
Gaudelli, N. M. et al. Programmable base editing of A*T to G*C in genomic DNA without DNA cleavage. Nature 551, 464–471 (2017).
Li, X. et al. Base editing with a Cpf1–cytidine deaminase fusion. Nat. Biotechnol. 36, 324–327 (2018).
Lei, L. et al. APOBEC3 induces mutations during repair of CRISPR–Cas9-generated DNA breaks. Nat. Struct. Mol. Biol. 25, 45–52 (2018).
Anzalone, A. V., Koblan, L. W. & Liu, D. R. Genome editing with CRISPR–Cas nucleases, base editors, transposases and prime editors. Nat. Biotechnol. 38, 824–844 (2020).
Yang, L. & Chen, J. A tale of two moieties: rapidly evolving CRISPR/Cas-based genome editing. Trends Biochem. Sci. 45, 874–888 (2020).
Kim, J. S. & Chen, J. Base editing of organellar DNA with programmable deaminases. Nat. Rev. Mol. Cell Biol. 25, 34–45 (2024).
Karimian, A., Ahmadi, Y. & Yousefi, B. Multiple functions of p21 in cell cycle, apoptosis and transcriptional regulation after DNA damage. DNA Repair 42, 63–71 (2016).
Bae, S., Park, J. & Kim, J. S. Cas-OFFinder: a fast and versatile algorithm that searches for potential off-target sites of Cas9 RNA-guided endonucleases. Bioinformatics 30, 1473–1475 (2014).
Kim, D. et al. Genome-wide target specificities of CRISPR RNA-guided programmable deaminases. Nat. Biotechnol. 35, 475–480 (2017).
Wang, X. et al. Efficient base editing in methylated regions with a human APOBEC3A–Cas9 fusion. Nat. Biotechnol. 36, 946–949 (2018).
Mayuranathan, T. et al. Potent and uniform fetal hemoglobin induction via base editing. Nat. Genet. 55, 1210–1220 (2023).
Liao, J. et al. Therapeutic adenine base editing of human hematopoietic stem cells. Nat. Commun. 14, 207 (2023).
Cradick, T. J., Qiu, P., Lee, C. M., Fine, E. J. & Bao, G. COSMID: a web-based tool for identifying and validating CRISPR/Cas off-target sites. Mol. Ther. Nucleic Acids 3, e214 (2014).
Cromer, M. K. et al. Comparative analysis of CRISPR off-target discovery tools following ex vivo editing of CD34+ hematopoietic stem and progenitor cells. Mol. Ther. 31, 1074–1087 (2023).
Wang, L. et al. Enhanced base editing by co-expression of free uracil DNA glycosylase inhibitor. Cell Res. 27, 1289–1292 (2017).
Komor, A. C. et al. Improved base excision repair inhibition and bacteriophage Mu Gam protein yields C:G-to-T:A base editors with higher efficiency and product purity. Sci. Adv. 3, eaao4774 (2017).
Yang, B., Yang, L. & Chen, J. Development and application of base editors. CRISPR J. 2, 91–104 (2019).
Taher, A., Vichinsky, E., Musallam, K., Cappellini, M. D. & Viprakasit, V. in Guidelines for the Management of Non Transfusion Dependent Thalassaemia (NTDT) (ed. Weatherall, D.) (Thalassaemia International Federation, 2013).
Kirk, P. et al. International reproducibility of single breathhold T2* MR for cardiac and liver iron assessment among five thalassemia centers. J. Magn. Reson. Imaging 32, 315–319 (2010).
Sharma, A. et al. CRISPR–Cas9 editing of the HBG1 and HBG2 promoters to treat sickle cell disease. N. Engl. J. Med. 389, 820–832 (2023).
Frangoul, H. et al. Exagamglogene autotemcel for severe sickle cell disease. N. Engl. J. Med. 390, 1649–1662 (2024).
Fucharoen, S., Shimizu, K. & Fukumaki, Y. A novel C-T transition within the distal CCAAT motif of the Gγ-globin gene in the Japanese HPFH: implication of factor binding in elevated fetal globin expression. Nucleic Acids Res. 18, 5245–5253 (1990).
Oner, R., Kutlar, F., Gu, L. H. & Huisman, T. H. The Georgia type of nondeletional hereditary persistence of fetal hemoglobin has a C→T mutation at nucleotide-114 of the Aγ-globin gene. Blood 77, 1124–1125 (1991).
Motum, P. I., Deng, Z. M., Huong, L. & Trent, R. J. The Australian type of nondeletional Gγ-HPFH has a C→G substitution at nucleotide -114 of the Gγ gene. Br. J. Haematol. 86, 219–221 (1994).
Zertal-Zidani, S. et al. A novel C→A transversion within the distal CCAAT motif of the Gγ-globin gene in the Algerian Gγβ+-hereditary persistence of fetal hemoglobin. Hemoglobin 23, 159–169 (1999).
Ribeil, J. A. et al. Ineffective erythropoiesis in β-thalassemia. Sci. World J. 2013, 394295 (2013).
Cancellieri, S. et al. Human genetic diversity alters off-target outcomes of therapeutic gene editing. Nat. Genet. 55, 34–43 (2023).
Breda, L. et al. In vivo hematopoietic stem cell modification by mRNA delivery. Science 381, 436–443 (2023).
Wognum, B., Yuan, N., Lai, B. & Miller, C. L. Colony forming cell assays for human hematopoietic progenitor cells. Methods Mol. Biol. 946, 267–283 (2013).
Mathias, L. A. et al. Ineffective erythropoiesis in β-thalassemia major is due to apoptosis at the polychromatophilic normoblast stage. Exp. Hematol. 28, 1343–1353 (2000).
Arlet, J. B. et al. HSP70 sequestration by free α-globin promotes ineffective erythropoiesis in β-thalassaemia. Nature 514, 242–246 (2014).
