Haploidentical Hematopoietic Stem Cell Transplantation for the Treatment of Congenital Dyserythropoietic Anemia Combined with Thalassemia: A Report of Two Cases

Haploidentical Hematopoietic Stem Cell Transplantation for the Treatment of Congenital Dyserythropoietic Anemia Combined with Thalassemia: A Report of Two Cases | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Case Report Haploidentical Hematopoietic Stem Cell Transplantation for the Treatment of Congenital Dyserythropoietic Anemia Combined with Thalassemia: A Report of Two Cases Changyu Yang, Jian Huang, Kun Yang, Changqing Wei, Lina Lu, Donmei Liu, and 4 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6740097/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 26 Sep, 2025 Read the published version in Annals of Hematology → Version 1 posted 9 You are reading this latest preprint version Abstract Congenital dyserythropoietic anemia (CDA) comprises a heterogeneous group of rare hereditary disorders characterized by ineffective erythropoiesis and often presents with clinical features that overlap with thalassemia. Hematopoietic stem cell transplantation (HSCT) remains the only definitive curative intervention for CDA; however, experience with haploidentical HSCT in this population is limited, and the procedure is associated with considerable challenges. We report two pediatric cases of CDA coexisting with thalassemia who underwent haploidentical related donor HSCT using a novel conditioning regimen comprising three alkylating agents. This was combined with graft-versus-host disease prophylaxis utilizing posttransplant cyclophosphamide and anti-thymocyte globulin. Both patients achieved sustained engraftment, transfusion independence, and remained free of severe transplant-related complications. These cases demonstrate the feasibility and therapeutic potential of haploidentical HSCT for patients with CDA, even in the context of concomitant thalassemia. Congenital dyserythropoietic anemia hematopoietic stem cell transplantation thalassemia anti-thymocyte globulin posttransplant cyclophosphamide Figures Figure 1 Introduction Congenital dyserythropoietic anemia (CDA) constitutes a rare spectrum of inherited erythroid disorders hallmarked by ineffective erythropoiesis, variable degrees of chronic anemia from birth, and progressive secondary iron overload. Its global incidence is estimated to be less than one per million individuals[ 1 – 3 ]. CDA is subclassified into three primary types (I, II, and III) based on clinical presentation, characteristic morphological features of erythroid precursors in the bone marrow, and associated genetic mutations. Cases that do not conform to these classifications are designated as “other types”. Thalassemia, a prevalent hemoglobinopathy characterized by impaired globin chain synthesis, is endemic in regions including the Mediterranean basin, the Middle East, Southeast Asia, and southern China. In the Guangxi Zhuang Autonomous Region of China, the carrier frequency for thalassemia mutations may reach up to 24%[ 4 – 6 ]. Owing to the high regional prevalence, the concomitant inheritance of thalassemia with other hereditary anemias is not infrequent. Our previous investigations have documented cases of thalassemia coexisting with hereditary spherocytosis[ 7 ] and, more rarely, with CDA[ 8 , 9 ]. Currently, hematopoietic stem cell transplantation (HSCT) is the sole curative therapy for CDA. However, the optimal conditioning regimen for haploidentical HSCT in this context remains undefined. In this report, we describe two pediatric patients diagnosed with CDA concomitant with thalassemia, both of whom underwent successful haploidentical HSCT from related donors. The transplantation employed a novel conditioning protocol incorporating three alkylating agents, in combination with graft-versus-host disease (GVHD) prophylaxis using posttransplant cyclophosphamide (PTCY) and anti-thymocyte globulin (ATG). Both patients achieved transfusion independence following transplantation. Case presentations Patient 1 was a 12-year-old male from the Guangxi Zhuang Autonomous Region, whose clinical characteristics have been previously detailed[ 9 ]. He first presented with anemia at 3 months of age and underwent genetic testing for thalassemia, which identified compound heterozygosity for -- SEA /α CS α and β CD41–42M /β N , consistent with a diagnosis of intermediate α-thalassemia in combination with β-thalassemia. Over time, he developed transfusion dependence and secondary iron overload. Notably, the clinical severity was disproportionate to the expected phenotype based on his thalassemia genotype, prompting further diagnostic evaluation. Whole-exome sequencing revealed compound heterozygous variants in the SEC23B gene: c.1508G > A (p.Arg503Gln) in exon 14 inherited from his father, and c.74C > A (p.Pro25His) in exon 2 inherited from his mother. These findings confirmed a diagnosis of CDA II coexisting with α-/β-thalassemia. In the absence of a suitable HLA-matched donor, his HLA-haploidentical father was selected as the stem cell donor. HLA antibody screening was negative. Pretransplant evaluation revealed mild iron overload, with a serum ferritin concentration of 1009.9 ng/mL. T2*-weighted magnetic resonance imaging (MRI) demonstrated mild hepatic iron deposition (liver iron concentration: 4.75 mg/g dry weight) without evidence of myocardial iron overload (cardiac T2*: 38 ms). The conditioning regimen included fludarabine, reduced-dose busulfan, thiotepa, and melphalan. GVHD prophylaxis consisted of PTCY and rabbit ATG. The infused graft comprised 16.4 × 10⁸ nucleated cells/kg and 19.0 × 10⁶ CD34⁺ cells/kg. Neutrophil and platelet engraftment occurred on day + 12 and day + 9, respectively. As of April 2025, the patient had been followed for 9 months post-transplantation. There was no evidence of cytomegalovirus or Epstein-Barr virus reactivation, veno-occlusive disease, or acute or chronic GVHD. The patient achieved transfusion independence within one month post-HSCT, with hemoglobin levels persistently exceeding 100 g/L; the most recent measurement was 105 g/L. Full donor chimerism has been maintained. Patient 2 was a 6-year-old female from the Guangxi Zhuang Autonomous Region who initially presented at 2 months of age with pallor and anemia. Hemoglobin electrophoresis did not detect hemoglobin H inclusions, and genetic analysis revealed a -- SEA /αα genotype, consistent with silent α-thalassemia. Despite this mild thalassemic genotype, she subsequently developed progressive transfusion dependence, requiring red blood cell transfusions approximately every 40 days. Given the disproportionate transfusion requirement relative to her thalassemia genotype, further diagnostic workup was undertaken. Bone marrow aspiration demonstrated marked erythroid hyperplasia accompanied by dysplastic morphological features. Extended molecular analysis identified compound heterozygous mutations in the CDAN1 gene: c.2059C > T (p.R687C), maternally inherited, and c.3268G > A (p.V1090I), identified as a de novo variant. These findings established a diagnosis of CDA I in conjunction with silent α-thalassemia. As with Patient 1, no HLA-matched donor was identified. Therefore, her HLA-haploidentical father was selected as the donor. Anti-HLA antibody screening was negative. Pretransplant assessment revealed severe iron overload, with a serum ferritin concentration of 2352 ng/mL. The conditioning regimen and GVHD prophylaxis mirrored that used for Patient 1, and the patient underwent haploidentical peripheral blood stem cell transplantation without procedural complications. Transfusion independence was achieved by day + 30 post-transplant. Follow-up targeted sequencing performed on day + 120 post-transplantation demonstrated the absence of both pathogenic CDAN1 variants, confirming full donor-derived hematopoiesis. As of April 2025, the patient remained disease-free at six months post-HSCT, with stable hemoglobin concentrations exceeding 100 g/L (most recent value: 101 g/L) and persistent full donor chimerism. Clinical characteristics of the two patients are summarized in Table 1 , treatment process of the two patients are summarized in Table 2 . The preconditioning procedure for haploidentical hematopoietic stem cell transplantation is shown in Fig. 1 . Table 1 Clinical characteristics of the two patients. Variables Patient 1 Patient 2 Age/Sex 12/male 6/female Height/Weight 133cm/27kg 110cm/17kg Age of transfusion (years) 0.25 0.16 Blood transfusion frequency 3 units/month 2 units/month Hemoglobin (g/dL) 82 67 Rreticulocyte (109/L) 43.3 47.8 NRBC(109/L) 0.05 0 TBIL (µmol/L) 31.6 19.9 IBIL (µmol/L) 24.2 13.5 LDH (U/L) 151 194 Serum ferritin (ng/ml) 1009 2352 Liver iron concentration (mg/g liver dry weight) 4.75 - Myocardial iron concentration (ms) 38 - Liver size 3.1cm below costal margin 3.6cm below costal margin Spleen size 13.8cm length, 4.7cm thickness, 4.5cm below costal margin 6.1cm length, 2.4cm thickness, 0 cm below costal margin CDA types type II type I Mutations in CDA SEC23B c.74C > A (p.Pro25His) c.1508G > A (p.Arg503Gln) CDAN1 c.2059C > T (p.R687C) c.3268G > A (p.V10901) Globin mutations -- SEA /α CS α, β CD41–42M /β N -- SEA /αα, β N /β N CDA, congenital dyserythropoietic anemia; IBIL, indirect bilirubin; LDH, lactate dehydrogenase; NRBC, nucleated red blood cells; TBIL, total bilirubin. Table 2 Complete treatment process of the two patients. Variables Patient 1 Patient 2 Donor HLA 6/12-matched father HLA 7/12-matched father Donor Age/Sex 40/male 30/male Pre-transplantation regimen Fludarabine : 30mg/m2 -7~-2 days; busulfan: 80mg/m2 -7~-6 days; thiotepa: 250mg/m2 -5 day; melphalan : 100mg/m2 -3 day Fludarabine: 30mg/m2 -7~-2 days; busulfan: 80mg/m2 -7~-6 days; thiotepa: 250mg/m2 -5 day; melphalan: 100mg/m2 -3 day Stem cell source PBSC PBSC MNC (×108 cells/kg) 16.4 20.1 CD34+ (×106 cells/kg) 19.0 19.5 GVHD prevention PTCY + 3d, +4d, 25mg/kg/d ATG − 2d, 2.0mg/kg/d; -1d, 2.5mg/kg/d Cyclosporine + 5d ~ 1year PTCY + 3d, +4d, 25mg/kg/d ATG − 2d, 2.0mg/kg/d; -1d, 2.5mg/kg/d Cyclosporine + 5d ~ 1year Neutrophil engraftment 12d 12d platelet engraftment 9d 12d STR for 180d complete chimerism complete chimerism Survival status after transplantation DFS for 9months DFS for 6 months ATG, Rabbit Anti-human T lymphocyte immunoglobulin; CDA, congenital dyserythropoietic anemia; DFS, disease-free survival; GVHD, graft versus host disease; HLA, human leukocyte antigen; MNC, mononuclear cell; MMF, mycophenolate mofetil; PBSC, peripheral blood stem cell; PTCY, post-transplant cyclophosphamide; STR, short tandem repeat Discussion In both cases, the diagnosis of CDA was initially delayed due to substantial clinical overlap with thalassemia. Each patient presented early in life with anemia and was initially diagnosed with thalassemia based on globin genotyping. However, the severity of clinical manifestations was disproportionate to the underlying thalassemic mutations, prompting additional evaluation. Comprehensive hematologic and molecular analyses subsequently revealed defining features of CDA, including erythroid dysplasia on bone marrow examination and pathogenic mutations in CDA-associated genes, thereby establishing the diagnosis. These cases underscore the diagnostic challenges encountered in regions with a high prevalence of hereditary anemias, where overlapping clinical phenotypes may obscure recognition of coexisting conditions. In such settings, subtle laboratory inconsistencies and phenotypic discordance should prompt consideration of alternative or concurrent diagnoses. Increasingly, accurate identification of these rare entities relies on advanced molecular diagnostics. CDA is characterized by ineffective erythropoiesis and defective erythroid maturation, with a heterogeneous clinical spectrum[ 1 ]. While some individuals may remain asymptomatic, approximately 20%-30% develop transfusion-dependent anemia[ 10 – 12 ], presenting with features such as pallor, jaundice, and splenomegaly, symptoms that also commonly occur in thalassemia[ 4 ]. In our cohort, both patients exhibited marked transfusion dependence and overt clinical symptoms, likely reflecting a synergistic burden from the co-inheritance of CDA and thalassemia. This phenotypic convergence further highlights the importance of a thorough and integrative diagnostic approach in complex inherited anemias. Published evidence with HSCT for CDA remains limited, particularly in the context of haploidentical donor transplantation. Most reported cases involve matched sibling or unrelated donors, employing conditioning regimens primarily based on busulfan, cyclophosphamide, melphalan, and ATG. GVHD prophylaxis in these settings typically includes cyclosporine and methotrexate, whereas PTCY-based approaches have been less commonly utilized[ 13 – 16 ]. A 2019 retrospective analysis by the European Society for Blood and Marrow Transplantation (EBMT) evaluated 39 patients with CDA who underwent matched donor HSCT; of these, 38 received myeloablative conditioning[ 14 ]. Similarly, a 2022 multicenter retrospective study from the Pediatric Transplant and Cellular Therapy Consortium (PTCTC) reported on 18 CDA patients, 17 of whom received grafts from matched donors. In that cohort, 12 underwent busulfan-based myeloablation, while 5 received reduced-intensity regimens incorporating fludarabine[ 13 ]. Despite full HLA matching, long-term outcomes remained modest, with 3-year event-free survival (EFS) rates of 45% for myeloablative regimens and 2-year EFS of 65% for reduced-intensity protocols. In our two cases, the unavailability of matched donors and the added hematologic burden posed by co-inherited thalassemia significantly increased transplant complexity and associated risks. A major obstacle in haploidentical HSCT for CDA is graft failure. The EBMT study reported a secondary graft failure rate of 12% at three years[ 14 ]. In the PTCTC analysis[ 13 ], graft failure occurred in four patients, including the only recipient of haploidentical HSCT. That individual received a bone marrow graft from the father following a conditioning regimen comprising busulfan, fludarabine, and melphalan, but experienced primary graft failure by day + 35. Salvage transplantation using a regimen of thiotepa, total body irradiation, and cyclosporine, followed by peripheral blood stem cells (PBSC) from the mother, ultimately achieved engraftment by day + 29. These findings suggest that busulfan-based regimens, though historically foundational, may be inadequate in addressing the underlying ineffective erythropoiesis characteristic of CDA. As such, there is a pressing need to develop alternative myeloablative strategies that enhance engraftment efficacy while maintaining an acceptable toxicity profile. The Transplant Conditioning Intensity (TCI) index, which serves as a predictor of transplant-related mortality[ 17 ], assigns a TCI score of 4.0 to the conventional busulfan/cyclosporine regimen. In our prior experience with haploidentical HSCT for hematologic malignancies, we employed a dual-alkylator BFM regimen consisting of fludarabine, melphalan (130 mg/m² for two consecutive days), and a single day of busulfan (100 mg/m²), which achieved a TCI of 3.0. This protocol was associated with a graft failure rate of less than 1% and a 2-year non-relapse mortality of 10.6%[ 18 ], reflecting the synergistic myeloablative effect of busulfan and melphalan. Considering the increased risk of graft failure in CDA patients with concomitant thalassemia undergoing haploidentical HSCT, we adapted the BFM regimen by incorporating thiotepa (250 mg/m² on day − 5) and reducing busulfan to 80 mg/m² over two days. Thiotepa, a third alkylating agent with both cytotoxic and immunosuppressive properties, has demonstrated utility in conditioning regimens for inherited anemias[ 19 ]. Despite the use of three alkylators, the modified regimen achieved a moderate TCI of 3.5, lower than that of the standard busulfan/cyclosporine protocol, suggesting an acceptable toxicity profile. To augment engraftment potential, high-dose grafts were administered, with CD34⁺ cell doses exceeding 18 × 10⁶ cells/kg in both patients. This combination of intensified yet balanced conditioning and optimized graft cell dose facilitated successful neutrophil engraftment by day + 12 and durable full donor chimerism over a six-month follow-up period. Importantly, no significant conditioning-related toxicities, such as venoocclusive disease, hemorrhagic cystitis, or thrombotic microangiopathy, were observed. GVHD remains a significant complication in haploidentical HSCT for CDA. In the EBMT cohort, 6 of 39 patients succumbed to GVHD-related complications[ 14 ]. The elevated GVHD risk in this population may be attributed to immune dysregulation secondary to prior transfusions and iron overload, a phenomenon also documented in thalassemia[ 20 ]. A meta-analysis of haploidentical HSCT in thalassemia reported grade II-IV acute GVHD rates of 22.3%, with no significant difference between PTCY-based and non-PTCY-based prophylactic regimens[ 21 ]. Recent data support the efficacy of dual GVHD prophylaxis combining PTCY and ATG. A 2023 multicenter study demonstrated that this dual approach, with PTCY doses ranging from 29–100 mg/kg and ATG doses between 2–10 mg/kg, significantly reduced both acute and chronic GVHD compared to single-agent regimens[ 22 ]. Given the use of PBSCs and high graft cell doses, both recognized GVHD risk factors[ 23 ], we adopted a combination prophylaxis strategy using half-dose PTCY (50 mg/kg total over days + 3 and + 4) and ATG (total dose 4.5 mg/kg). This regimen effectively prevented acute GVHD, with no cases of chronic GVHD reported during the follow-up period. Nonetheless, long-term surveillance remains necessary to fully evaluate the safety and durability of this approach. Conclusion Haploidentical HSCT for CDA remains a complex undertaking, particularly due to the heightened risks of graft failure and GVHD. At our institution, we implemented an intensified yet tolerable conditioning protocol incorporating three alkylating agents, alongside a dual-agent GVHD prophylaxis regimen consisting of PTCY and ATG. Both patients achieved prompt and durable engraftment, transfusion independence, and remained free of GVHD throughout follow-up. These results underscore the potential feasibility and therapeutic efficacy of haploidentical HSCT in the treatment of CDA, especially in cases further complicated by co-inherited hematologic disorders such as thalassemia. Nonetheless, validation of this approach through larger, multicenter studies with extended follow-up is essential to optimize conditioning intensity and GVHD prophylaxis strategies for broader clinical implementation. Declarations Author contributions Changyu Yang: Writing- original draft, Writing- review & editing. Jian Huang, Kun Yang, Changqing Wei, Lina Lu, Donmei Liu, Beibei Yang: Data collection, Investigation, Methodology. Guiping Liao, Xiaolin Yin, Writing- review & editing. Yali Zhou: Conceptualization, project administration, Writing- review & editing. Xiaolin Yin provided the funding support. Yali Zhou revised the final draft. All authors reviewed and edited the final manuscript before submission. Funding This work was supported by the Scientific Research Project of Guangxi Zhuang Autonomous Region Health Committeed [ZA20231086], the Scientific Research Fund Project of Guangzhou City Life Oasis Public Welfare Service Center[GZLZ-HEMA-008] Data availability No datasets were generated or analysed during the current study. Ethical approval Informed consent was obtained from the patients for the publication of any potentially identifiable data included in this article. Competing interests The authors declare no competing interests. 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To view a copy of this licence, visit http://creativecommons.org/licenses/by-nc-nd/4.0/. References Iolascon A, Andolfo I, Russo R (2020) Congenital dyserythropoietic anemias [J]. Blood 136(11):1274–1283. http://dio.org/10.1182/blood.2019000948 Heimpel H, Matuschek A, Ahmed M et al (2010) Frequency of congenital dyserythropoietic anemias in Europe [J]. Eur J Haematol 85(1):20–25 Gulbis B, Eleftheriou A, Angastiniotis M et al (2010) Epidemiology of rare anaemias in Europe [J]. Adv Exp Med Biol 686:375–396. http://dio.org/10.1007/978-90-481-9485-8_22 Kattamis A, Kwiatkowski JL, Aydinok Y (2022) Thalassaemia [J]. Lancet 399(10343):2310–2324. http://dio.org/10.1016/s0140-6736(22)00536-0 Lai K, Huang G, Su L et al (2017) The prevalence of thalassemia in mainland China: evidence from epidemiological surveys [J]. Sci Rep 7(1):920. http://dio.org/10.1038/s41598-017-00967-2 Li XY, Lan J, Luo RG et al (2009) [Epidemiological investigation and genotype of thalassemia on middle school students in Chongzuo, Guangxi] [J]. Zhonghua Liu Xing Bing Xue Za Zhi 30(6):567–570 Yang K, Ren Q, Wu Y et al (2019) A Case of Hereditary Spherocytosis Caused by a Novel Homozygous Mutation in the SPTB Gene Misdiagnosed as β-Thalassemia Intermedia Due to a KLF1 Gene Mutation [J]. Hemoglobin 43(2):140–144. http://dio.org/10.1080/03630269.2019.1620764 Yang K, Nie W, Huang Q et al (2023) Hematopoietic cell transplantation for congenital dyserythropoietic anemia IV caused by compound heterozygous KLF1 mutations [J]. Ann Hematol 102(6):1621–1624. http://dio.org/10.1007/s00277-023-05175-9 Liao G, Lu TT, Wei C et al (2024) A Case of Congenital Dyserythropoietic Anemia Masked by Hemoglobin H Disease [J]. Mediterr J Hematol Infect Dis 16(1):e2024059. http://dio.org/10.4084/mjhid.2024.059 Marra R, Nostroso A, Rosato BE et al (2024) Unveiling the genetic landscape of suspected congenital dyserythropoietic anemia type I: A retrospective cohort study of 36 patients [J]. Am J Hematol 99(8):1511–1522. http://dio.org/10.1002/ajh.27350 Russo R, Gambale A, Langella C et al (2014) Retrospective cohort study of 205 cases with congenital dyserythropoietic anemia type II: definition of clinical and molecular spectrum and identification of new diagnostic scores [J]. Am J Hematol 89(10):E169–175. http://dio.org/10.1002/ajh.23800 Dass J, Nayak AR, Puri V et al (2024) Congenital dyserythropoietic anemia in children: Case series with review of literature [J]. Pediatr Hematol Oncol J 9(2):55–61. http://dio.org/https://doi.org/ 10.1016/j.phoj.2024.02.004 Rangarajan HG, Stanek JR, Abdel-Azim H et al (2022) Hematopoietic Cell Transplantation for Congenital Dyserythropoietic Anemia: A Report from the Pediatric Transplant and Cellular Therapy Consortium [J]. Transplantation and Cellular Therapy, 28(6): 329. e321-329.e329.http://dio.org/10.1016/j.jtct.2022.03.007 Miano M, Eikema DJ, Aljurf M et al (2019) Stem cell transplantation for congenital dyserythropoietic anemia: an analysis from the European Society for Blood and Marrow Transplantation [J]. Haematologica 104(8):e335–e339. http://dio.org/10.3324/haematol.2018.206623 Braun M, Wölfl M, Wiegering V et al (2014) Successful treatment of an infant with CDA type II by intrauterine transfusions and postnatal stem cell transplantation [J]. Pediatr Blood Cancer 61(4):743–745. http://dio.org/10.1002/pbc.24786 Remacha AF, Badell I, Pujol-Moix N et al (2002) Hydrops fetalis-associated congenital dyserythropoietic anemia treated with intrauterine transfusions and bone marrow transplantation [J]. Blood 100(1):356–358. http://dio.org/10.1182/blood-2001-12-0351 Spyridonidis A, Labopin M, Savani BN et al (2020) Redefining and measuring transplant conditioning intensity in current era: a study in acute myeloid leukemia patients [J]. Bone Marrow Transpl 55(6):1114–1125. http://dio.org/10.1038/s41409-020-0803-y Jiang J, Li X, Wu D et al (2024) Fludarabine, busulfan, and melphalan conditioning regimen in allogeneic hematopoietic stem cell transplantation for adult patients with myeloid malignancies: A multicenter retrospective study [J]. EJHaem 5(4):757–767. http://dio.org/10.1002/jha2.947 Faulkner L, Uderzo C, Khalid S et al (2017) ATG vs thiotepa with busulfan and cyclophosphamide in matched-related bone marrow transplantation for thalassemia [J]. Blood Adv 1(13):792–801. http://dio.org/10.1182/bloodadvances.2016004119 Vinchi F, Sparla R, Passos ST et al (2021) Vasculo-toxic and pro-inflammatory action of unbound haemoglobin, haem and iron in transfusion-dependent patients with haemolytic anaemias [J]. Br J Haematol 193(3):637–658. http://dio.org/10.1111/bjh.17361 Xiao H, Huang Q, Lai Y et al (2025) Haploidentical Hematopoietic Stem Cell Transplantation in Pediatric Transfusion-Dependent Thalassemia: A Systematic Review and Meta-Analysis [J]. Transpl Cell Ther 31(2):101e101. 101.e112.http://dio.org/10.1016/j.jtct.2024.12.001 Duléry R, Brissot E, Mohty M (2023) Combining post-transplant cyclophosphamide with antithymocyte globulin for graft-versus-host disease prophylaxis in hematological malignancies [J]. Blood Rev 62:101080. http://dio.org/10.1016/j.blre.2023.101080 Lacan C, Lambert J, Forcade E et al (2024) Bone marrow graft versus peripheral blood graft in haploidentical hematopoietic stem cells transplantation: a retrospective analysis in1344 patients of SFGM-TC registry [J]. J Hematol Oncol 17(1):2. http://dio.org/10.1186/s13045-023-01515-4 Additional Declarations No competing interests reported. Cite Share Download PDF Status: Published Journal Publication published 26 Sep, 2025 Read the published version in Annals of Hematology → Version 1 posted Editorial decision: Revision requested 04 Aug, 2025 Reviews received at journal 25 Jul, 2025 Reviews received at journal 19 Jun, 2025 Reviewers agreed at journal 14 Jun, 2025 Reviewers agreed at journal 11 Jun, 2025 Reviewers invited by journal 11 Jun, 2025 Editor assigned by journal 02 Jun, 2025 Submission checks completed at journal 02 Jun, 2025 First submitted to journal 24 May, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-6740097","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Case Report","associatedPublications":[],"authors":[{"id":469982918,"identity":"44d7e277-3284-42e9-89fc-f814a33bb5aa","order_by":0,"name":"Changyu Yang","email":"","orcid":"","institution":"Department of Hematology, The 923rd Hospital of the Joint Logistics Support Force of the People’s Liberation Army","correspondingAuthor":false,"prefix":"","firstName":"Changyu","middleName":"","lastName":"Yang","suffix":""},{"id":469982919,"identity":"9f0aa436-08ac-4a48-afc9-f0522f9d0ab8","order_by":1,"name":"Jian Huang","email":"","orcid":"","institution":"Department of Hematology, The 923rd Hospital of the Joint Logistics Support Force of the People’s Liberation Army","correspondingAuthor":false,"prefix":"","firstName":"Jian","middleName":"","lastName":"Huang","suffix":""},{"id":469982920,"identity":"a2f44471-3ec9-43e3-a292-26f2f7059697","order_by":2,"name":"Kun Yang","email":"","orcid":"","institution":"Department of Hematology, The 923rd Hospital of the Joint Logistics Support Force of the People’s Liberation Army","correspondingAuthor":false,"prefix":"","firstName":"Kun","middleName":"","lastName":"Yang","suffix":""},{"id":469982921,"identity":"83717c73-7755-4c92-af45-37787ef258df","order_by":3,"name":"Changqing Wei","email":"","orcid":"","institution":"Department of Hematology, The 923rd Hospital of the Joint Logistics Support Force of the People’s Liberation Army","correspondingAuthor":false,"prefix":"","firstName":"Changqing","middleName":"","lastName":"Wei","suffix":""},{"id":469982922,"identity":"690debac-2c32-492c-ab6b-2b7662bc87e6","order_by":4,"name":"Lina Lu","email":"","orcid":"","institution":"Department of Hematology, The 923rd Hospital of the Joint Logistics Support Force of the People’s Liberation Army","correspondingAuthor":false,"prefix":"","firstName":"Lina","middleName":"","lastName":"Lu","suffix":""},{"id":469982923,"identity":"6622f9dd-0247-47ee-82ed-0b43eb417356","order_by":5,"name":"Donmei Liu","email":"","orcid":"","institution":"Department of Hematology, The 923rd Hospital of the Joint Logistics Support Force of the People’s Liberation Army","correspondingAuthor":false,"prefix":"","firstName":"Donmei","middleName":"","lastName":"Liu","suffix":""},{"id":469982924,"identity":"894bbd78-281b-424e-b7b7-536c95b127de","order_by":6,"name":"Beibei Yang","email":"","orcid":"","institution":"Department of Hematology, The 923rd Hospital of the Joint Logistics Support Force of the People’s Liberation Army","correspondingAuthor":false,"prefix":"","firstName":"Beibei","middleName":"","lastName":"Yang","suffix":""},{"id":469982925,"identity":"90445a64-81b9-48fd-bb06-ff4753f695f3","order_by":7,"name":"Guiping Liao","email":"","orcid":"","institution":"Department of Hematology, The 923rd Hospital of the Joint Logistics Support Force of the People’s Liberation Army","correspondingAuthor":false,"prefix":"","firstName":"Guiping","middleName":"","lastName":"Liao","suffix":""},{"id":469982926,"identity":"f2be01b3-5fef-496a-8fb8-c336a2683c54","order_by":8,"name":"Xiaolin Yin","email":"","orcid":"","institution":"Department of Hematology, The 923rd Hospital of the Joint Logistics Support Force of the People’s Liberation Army","correspondingAuthor":false,"prefix":"","firstName":"Xiaolin","middleName":"","lastName":"Yin","suffix":""},{"id":469982928,"identity":"1f8a832b-6e0c-446d-b817-bdbf434bb032","order_by":9,"name":"Yali Zhou","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAz0lEQVRIie3RsQrCMBCA4SuFdAm4Xidf4SbpEPBBXFKETDoJolCwInTtWsGX6BsUAu1SnFs6+gJO4uBgwcWt6SaYf74P7jgAm+0Hm0x19cQdHhIvNiR+xiQGtXBSXhgSajjhPlHOOZOmm3UxUZtol9pb3kAkFoPCuRQyzK6aUac2AZRqHQ8RF2Shcas5dasZOrEeJgzC4+nFNFJbGxKOSxcwUeRn3JAgLxlgLeSE97dIk1vmVfqA/pWSeTpv7pEYJt8RyjHjHzJW2Gw223/0BvoaQULKT4rlAAAAAElFTkSuQmCC","orcid":"","institution":"Department of Hematology, The 923rd Hospital of the Joint Logistics Support Force of the People’s Liberation Army","correspondingAuthor":true,"prefix":"","firstName":"Yali","middleName":"","lastName":"Zhou","suffix":""}],"badges":[],"createdAt":"2025-05-24 16:23:23","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6740097/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6740097/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s00277-025-06615-4","type":"published","date":"2025-09-26T15:57:55+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":84689647,"identity":"2105de77-5eb6-4089-94ea-9adcad4342db","added_by":"auto","created_at":"2025-06-16 09:31:29","extension":"jpeg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":130103,"visible":true,"origin":"","legend":"\u003cp\u003ePreconditioning procedure for haploidentical hematopoietic stem cell transplantation.\u003c/p\u003e","description":"","filename":"floatimage1.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-6740097/v1/4c77fe7f1261d195cf08702f.jpeg"},{"id":92430769,"identity":"db2d6bbd-3fcb-4cd9-aed9-fa44834e9877","added_by":"auto","created_at":"2025-09-29 16:07:47","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":614817,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6740097/v1/3e59eff4-4fe1-4b36-8133-593b70b22812.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Haploidentical Hematopoietic Stem Cell Transplantation for the Treatment of Congenital Dyserythropoietic Anemia Combined with Thalassemia: A Report of Two Cases","fulltext":[{"header":"Introduction","content":"\u003cp\u003eCongenital dyserythropoietic anemia (CDA) constitutes a rare spectrum of inherited erythroid disorders hallmarked by ineffective erythropoiesis, variable degrees of chronic anemia from birth, and progressive secondary iron overload. Its global incidence is estimated to be less than one per million individuals[\u003cspan additionalcitationids=\"CR2\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. CDA is subclassified into three primary types (I, II, and III) based on clinical presentation, characteristic morphological features of erythroid precursors in the bone marrow, and associated genetic mutations. Cases that do not conform to these classifications are designated as \u0026ldquo;other types\u0026rdquo;. Thalassemia, a prevalent hemoglobinopathy characterized by impaired globin chain synthesis, is endemic in regions including the Mediterranean basin, the Middle East, Southeast Asia, and southern China. In the Guangxi Zhuang Autonomous Region of China, the carrier frequency for thalassemia mutations may reach up to 24%[\u003cspan additionalcitationids=\"CR5\" citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. Owing to the high regional prevalence, the concomitant inheritance of thalassemia with other hereditary anemias is not infrequent. Our previous investigations have documented cases of thalassemia coexisting with hereditary spherocytosis[\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e] and, more rarely, with CDA[\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eCurrently, hematopoietic stem cell transplantation (HSCT) is the sole curative therapy for CDA. However, the optimal conditioning regimen for haploidentical HSCT in this context remains undefined. In this report, we describe two pediatric patients diagnosed with CDA concomitant with thalassemia, both of whom underwent successful haploidentical HSCT from related donors. The transplantation employed a novel conditioning protocol incorporating three alkylating agents, in combination with graft-versus-host disease (GVHD) prophylaxis using posttransplant cyclophosphamide (PTCY) and anti-thymocyte globulin (ATG). Both patients achieved transfusion independence following transplantation.\u003c/p\u003e"},{"header":"Case presentations","content":"\u003cp\u003ePatient 1 was a 12-year-old male from the Guangxi Zhuang Autonomous Region, whose clinical characteristics have been previously detailed[\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. He first presented with anemia at 3 months of age and underwent genetic testing for thalassemia, which identified compound heterozygosity for --\u003csup\u003eSEA\u003c/sup\u003e/α\u003csup\u003eCS\u003c/sup\u003eα and β\u003csup\u003eCD41\u0026ndash;42M\u003c/sup\u003e/β\u003csup\u003eN\u003c/sup\u003e, consistent with a diagnosis of intermediate α-thalassemia in combination with β-thalassemia. Over time, he developed transfusion dependence and secondary iron overload. Notably, the clinical severity was disproportionate to the expected phenotype based on his thalassemia genotype, prompting further diagnostic evaluation. Whole-exome sequencing revealed compound heterozygous variants in the \u003cem\u003eSEC23B\u003c/em\u003e gene: c.1508G\u0026thinsp;\u0026gt;\u0026thinsp;A (p.Arg503Gln) in exon 14 inherited from his father, and c.74C\u0026thinsp;\u0026gt;\u0026thinsp;A (p.Pro25His) in exon 2 inherited from his mother. These findings confirmed a diagnosis of CDA II coexisting with α-/β-thalassemia.\u003c/p\u003e \u003cp\u003eIn the absence of a suitable HLA-matched donor, his HLA-haploidentical father was selected as the stem cell donor. HLA antibody screening was negative. Pretransplant evaluation revealed mild iron overload, with a serum ferritin concentration of 1009.9 ng/mL. T2*-weighted magnetic resonance imaging (MRI) demonstrated mild hepatic iron deposition (liver iron concentration: 4.75 mg/g dry weight) without evidence of myocardial iron overload (cardiac T2*: 38 ms). The conditioning regimen included fludarabine, reduced-dose busulfan, thiotepa, and melphalan. GVHD prophylaxis consisted of PTCY and rabbit ATG. The infused graft comprised 16.4 \u0026times; 10⁸ nucleated cells/kg and 19.0 \u0026times; 10⁶ CD34⁺ cells/kg. Neutrophil and platelet engraftment occurred on day\u0026thinsp;+\u0026thinsp;12 and day\u0026thinsp;+\u0026thinsp;9, respectively. As of April 2025, the patient had been followed for 9 months post-transplantation. There was no evidence of cytomegalovirus or Epstein-Barr virus reactivation, veno-occlusive disease, or acute or chronic GVHD. The patient achieved transfusion independence within one month post-HSCT, with hemoglobin levels persistently exceeding 100 g/L; the most recent measurement was 105 g/L. Full donor chimerism has been maintained.\u003c/p\u003e \u003cp\u003ePatient 2 was a 6-year-old female from the Guangxi Zhuang Autonomous Region who initially presented at 2 months of age with pallor and anemia. Hemoglobin electrophoresis did not detect hemoglobin H inclusions, and genetic analysis revealed a --\u003csup\u003eSEA\u003c/sup\u003e/αα genotype, consistent with silent α-thalassemia. Despite this mild thalassemic genotype, she subsequently developed progressive transfusion dependence, requiring red blood cell transfusions approximately every 40 days. Given the disproportionate transfusion requirement relative to her thalassemia genotype, further diagnostic workup was undertaken. Bone marrow aspiration demonstrated marked erythroid hyperplasia accompanied by dysplastic morphological features. Extended molecular analysis identified compound heterozygous mutations in the \u003cem\u003eCDAN1\u003c/em\u003e gene: c.2059C\u0026thinsp;\u0026gt;\u0026thinsp;T (p.R687C), maternally inherited, and c.3268G\u0026thinsp;\u0026gt;\u0026thinsp;A (p.V1090I), identified as a de novo variant. These findings established a diagnosis of CDA I in conjunction with silent α-thalassemia.\u003c/p\u003e \u003cp\u003eAs with Patient 1, no HLA-matched donor was identified. Therefore, her HLA-haploidentical father was selected as the donor. Anti-HLA antibody screening was negative. Pretransplant assessment revealed severe iron overload, with a serum ferritin concentration of 2352 ng/mL. The conditioning regimen and GVHD prophylaxis mirrored that used for Patient 1, and the patient underwent haploidentical peripheral blood stem cell transplantation without procedural complications. Transfusion independence was achieved by day\u0026thinsp;+\u0026thinsp;30 post-transplant. Follow-up targeted sequencing performed on day\u0026thinsp;+\u0026thinsp;120 post-transplantation demonstrated the absence of both pathogenic \u003cem\u003eCDAN1\u003c/em\u003e variants, confirming full donor-derived hematopoiesis. As of April 2025, the patient remained disease-free at six months post-HSCT, with stable hemoglobin concentrations exceeding 100 g/L (most recent value: 101 g/L) and persistent full donor chimerism. Clinical characteristics of the two patients are summarized in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e, treatment process of the two patients are summarized in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e. The preconditioning procedure for haploidentical hematopoietic stem cell transplantation is shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eClinical characteristics of the two patients.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"3\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVariables\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePatient 1\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003ePatient 2\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAge/Sex\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e12/male\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6/female\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHeight/Weight\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e133cm/27kg\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e110cm/17kg\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAge of transfusion (years)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.16\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBlood transfusion frequency\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3 units/month\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2 units/month\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHemoglobin (g/dL)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e82\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e67\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eRreticulocyte (109/L)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e43.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e47.8\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNRBC(109/L)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.05\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTBIL (\u0026micro;mol/L)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e31.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e19.9\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eIBIL (\u0026micro;mol/L)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e24.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e13.5\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLDH (U/L)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e151\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e194\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSerum ferritin (ng/ml)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1009\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2352\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLiver iron concentration (mg/g liver dry weight)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e4.75\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMyocardial iron concentration (ms)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e38\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLiver size\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3.1cm below costal margin\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3.6cm below costal margin\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSpleen size\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e13.8cm length, 4.7cm thickness, 4.5cm below costal margin\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e6.1cm length, 2.4cm thickness,\u003c/p\u003e \u003cp\u003e0 cm below costal margin\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCDA types\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003etype II\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003etype I\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMutations in CDA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003eSEC23B\u003c/em\u003e\u003c/p\u003e \u003cp\u003ec.74C\u0026thinsp;\u0026gt;\u0026thinsp;A (p.Pro25His)\u003c/p\u003e \u003cp\u003ec.1508G\u0026thinsp;\u0026gt;\u0026thinsp;A (p.Arg503Gln)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cem\u003eCDAN1\u003c/em\u003e\u003c/p\u003e \u003cp\u003ec.2059C\u0026thinsp;\u0026gt;\u0026thinsp;T (p.R687C)\u003c/p\u003e \u003cp\u003ec.3268G\u0026thinsp;\u0026gt;\u0026thinsp;A (p.V10901)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGlobin mutations\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e--\u003csup\u003eSEA\u003c/sup\u003e/α\u003csup\u003eCS\u003c/sup\u003eα, β\u003csup\u003eCD41\u0026ndash;42M\u003c/sup\u003e/β\u003csup\u003eN\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e--\u003csup\u003eSEA\u003c/sup\u003e/αα, β\u003csup\u003eN\u003c/sup\u003e/β\u003csup\u003eN\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"3\"\u003eCDA, congenital dyserythropoietic anemia; IBIL, indirect bilirubin; LDH, lactate dehydrogenase; NRBC, nucleated red blood cells; TBIL, total bilirubin.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eComplete treatment process of the two patients.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"3\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVariables\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePatient 1\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003ePatient 2\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDonor\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eHLA 6/12-matched father\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eHLA 7/12-matched father\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eDonor Age/Sex\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e40/male\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003e30/male\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePre-transplantation regimen\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003eFludarabine\u003c/b\u003e: 30mg/m2 -7~-2 days; busulfan: 80mg/m2 -7~-6 days; thiotepa: 250mg/m2 -5 day; \u003cb\u003emelphalan\u003c/b\u003e: 100mg/m2 -3 day\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eFludarabine: 30mg/m2 -7~-2 days; busulfan: 80mg/m2 -7~-6 days; thiotepa: 250mg/m2 -5 day; melphalan: 100mg/m2 -3 day\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eStem cell source\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003ePBSC\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003ePBSC\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMNC (\u0026times;108 cells/kg)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e16.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e20.1\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCD34+ (\u0026times;106 cells/kg)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e19.0\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003e19.5\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGVHD prevention\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePTCY\u0026thinsp;+\u0026thinsp;3d, +4d, 25mg/kg/d\u003c/p\u003e \u003cp\u003eATG \u0026minus;\u0026thinsp;2d, 2.0mg/kg/d; -1d, 2.5mg/kg/d\u003c/p\u003e \u003cp\u003eCyclosporine\u0026thinsp;+\u0026thinsp;5d\u0026thinsp;~\u0026thinsp;1year\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003ePTCY\u0026thinsp;+\u0026thinsp;3d, +4d, 25mg/kg/d\u003c/p\u003e \u003cp\u003eATG \u0026minus;\u0026thinsp;2d, 2.0mg/kg/d; -1d, 2.5mg/kg/d\u003c/p\u003e \u003cp\u003eCyclosporine\u0026thinsp;+\u0026thinsp;5d\u0026thinsp;~\u0026thinsp;1year\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNeutrophil engraftment\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e12d\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003e12d\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eplatelet engraftment\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e9d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e12d\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSTR for 180d\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003ecomplete chimerism\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003ecomplete chimerism\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSurvival status\u003c/p\u003e \u003cp\u003eafter transplantation\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eDFS for 9months\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eDFS for 6 months\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"3\"\u003eATG, Rabbit Anti-human T lymphocyte immunoglobulin; CDA, congenital dyserythropoietic anemia; DFS, disease-free survival; GVHD, graft versus host disease; HLA, human leukocyte antigen; MNC, mononuclear cell; MMF, mycophenolate mofetil; PBSC, peripheral blood stem cell; PTCY, post-transplant cyclophosphamide; STR, short tandem repeat\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eIn both cases, the diagnosis of CDA was initially delayed due to substantial clinical overlap with thalassemia. Each patient presented early in life with anemia and was initially diagnosed with thalassemia based on globin genotyping. However, the severity of clinical manifestations was disproportionate to the underlying thalassemic mutations, prompting additional evaluation. Comprehensive hematologic and molecular analyses subsequently revealed defining features of CDA, including erythroid dysplasia on bone marrow examination and pathogenic mutations in CDA-associated genes, thereby establishing the diagnosis. These cases underscore the diagnostic challenges encountered in regions with a high prevalence of hereditary anemias, where overlapping clinical phenotypes may obscure recognition of coexisting conditions. In such settings, subtle laboratory inconsistencies and phenotypic discordance should prompt consideration of alternative or concurrent diagnoses. Increasingly, accurate identification of these rare entities relies on advanced molecular diagnostics. CDA is characterized by ineffective erythropoiesis and defective erythroid maturation, with a heterogeneous clinical spectrum[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. While some individuals may remain asymptomatic, approximately 20%-30% develop transfusion-dependent anemia[\u003cspan additionalcitationids=\"CR11\" citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e], presenting with features such as pallor, jaundice, and splenomegaly, symptoms that also commonly occur in thalassemia[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. In our cohort, both patients exhibited marked transfusion dependence and overt clinical symptoms, likely reflecting a synergistic burden from the co-inheritance of CDA and thalassemia. This phenotypic convergence further highlights the importance of a thorough and integrative diagnostic approach in complex inherited anemias.\u003c/p\u003e \u003cp\u003ePublished evidence with HSCT for CDA remains limited, particularly in the context of haploidentical donor transplantation. Most reported cases involve matched sibling or unrelated donors, employing conditioning regimens primarily based on busulfan, cyclophosphamide, melphalan, and ATG. GVHD prophylaxis in these settings typically includes cyclosporine and methotrexate, whereas PTCY-based approaches have been less commonly utilized[\u003cspan additionalcitationids=\"CR14 CR15\" citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. A 2019 retrospective analysis by the European Society for Blood and Marrow Transplantation (EBMT) evaluated 39 patients with CDA who underwent matched donor HSCT; of these, 38 received myeloablative conditioning[\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. Similarly, a 2022 multicenter retrospective study from the Pediatric Transplant and Cellular Therapy Consortium (PTCTC) reported on 18 CDA patients, 17 of whom received grafts from matched donors. In that cohort, 12 underwent busulfan-based myeloablation, while 5 received reduced-intensity regimens incorporating fludarabine[\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. Despite full HLA matching, long-term outcomes remained modest, with 3-year event-free survival (EFS) rates of 45% for myeloablative regimens and 2-year EFS of 65% for reduced-intensity protocols.\u003c/p\u003e \u003cp\u003eIn our two cases, the unavailability of matched donors and the added hematologic burden posed by co-inherited thalassemia significantly increased transplant complexity and associated risks. A major obstacle in haploidentical HSCT for CDA is graft failure. The EBMT study reported a secondary graft failure rate of 12% at three years[\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. In the PTCTC analysis[\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e], graft failure occurred in four patients, including the only recipient of haploidentical HSCT. That individual received a bone marrow graft from the father following a conditioning regimen comprising busulfan, fludarabine, and melphalan, but experienced primary graft failure by day\u0026thinsp;+\u0026thinsp;35. Salvage transplantation using a regimen of thiotepa, total body irradiation, and cyclosporine, followed by peripheral blood stem cells (PBSC) from the mother, ultimately achieved engraftment by day\u0026thinsp;+\u0026thinsp;29. These findings suggest that busulfan-based regimens, though historically foundational, may be inadequate in addressing the underlying ineffective erythropoiesis characteristic of CDA. As such, there is a pressing need to develop alternative myeloablative strategies that enhance engraftment efficacy while maintaining an acceptable toxicity profile.\u003c/p\u003e \u003cp\u003eThe Transplant Conditioning Intensity (TCI) index, which serves as a predictor of transplant-related mortality[\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e], assigns a TCI score of 4.0 to the conventional busulfan/cyclosporine regimen. In our prior experience with haploidentical HSCT for hematologic malignancies, we employed a dual-alkylator BFM regimen consisting of fludarabine, melphalan (130 mg/m\u0026sup2; for two consecutive days), and a single day of busulfan (100 mg/m\u0026sup2;), which achieved a TCI of 3.0. This protocol was associated with a graft failure rate of less than 1% and a 2-year non-relapse mortality of 10.6%[\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e], reflecting the synergistic myeloablative effect of busulfan and melphalan. Considering the increased risk of graft failure in CDA patients with concomitant thalassemia undergoing haploidentical HSCT, we adapted the BFM regimen by incorporating thiotepa (250 mg/m\u0026sup2; on day \u0026minus;\u0026thinsp;5) and reducing busulfan to 80 mg/m\u0026sup2; over two days. Thiotepa, a third alkylating agent with both cytotoxic and immunosuppressive properties, has demonstrated utility in conditioning regimens for inherited anemias[\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]. Despite the use of three alkylators, the modified regimen achieved a moderate TCI of 3.5, lower than that of the standard busulfan/cyclosporine protocol, suggesting an acceptable toxicity profile. To augment engraftment potential, high-dose grafts were administered, with CD34⁺ cell doses exceeding 18 \u0026times; 10⁶ cells/kg in both patients. This combination of intensified yet balanced conditioning and optimized graft cell dose facilitated successful neutrophil engraftment by day\u0026thinsp;+\u0026thinsp;12 and durable full donor chimerism over a six-month follow-up period. Importantly, no significant conditioning-related toxicities, such as venoocclusive disease, hemorrhagic cystitis, or thrombotic microangiopathy, were observed.\u003c/p\u003e \u003cp\u003eGVHD remains a significant complication in haploidentical HSCT for CDA. In the EBMT cohort, 6 of 39 patients succumbed to GVHD-related complications[\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. The elevated GVHD risk in this population may be attributed to immune dysregulation secondary to prior transfusions and iron overload, a phenomenon also documented in thalassemia[\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. A meta-analysis of haploidentical HSCT in thalassemia reported grade II-IV acute GVHD rates of 22.3%, with no significant difference between PTCY-based and non-PTCY-based prophylactic regimens[\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. Recent data support the efficacy of dual GVHD prophylaxis combining PTCY and ATG. A 2023 multicenter study demonstrated that this dual approach, with PTCY doses ranging from 29\u0026ndash;100 mg/kg and ATG doses between 2\u0026ndash;10 mg/kg, significantly reduced both acute and chronic GVHD compared to single-agent regimens[\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. Given the use of PBSCs and high graft cell doses, both recognized GVHD risk factors[\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e], we adopted a combination prophylaxis strategy using half-dose PTCY (50 mg/kg total over days\u0026thinsp;+\u0026thinsp;3 and +\u0026thinsp;4) and ATG (total dose 4.5 mg/kg). This regimen effectively prevented acute GVHD, with no cases of chronic GVHD reported during the follow-up period. Nonetheless, long-term surveillance remains necessary to fully evaluate the safety and durability of this approach.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eHaploidentical HSCT for CDA remains a complex undertaking, particularly due to the heightened risks of graft failure and GVHD. At our institution, we implemented an intensified yet tolerable conditioning protocol incorporating three alkylating agents, alongside a dual-agent GVHD prophylaxis regimen consisting of PTCY and ATG. Both patients achieved prompt and durable engraftment, transfusion independence, and remained free of GVHD throughout follow-up. These results underscore the potential feasibility and therapeutic efficacy of haploidentical HSCT in the treatment of CDA, especially in cases further complicated by co-inherited hematologic disorders such as thalassemia. Nonetheless, validation of this approach through larger, multicenter studies with extended follow-up is essential to optimize conditioning intensity and GVHD prophylaxis strategies for broader clinical implementation.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003eAuthor contributions Changyu Yang: Writing- original draft, Writing- review \u0026amp; editing. Jian Huang, Kun Yang, Changqing Wei, Lina Lu, Donmei Liu, Beibei Yang: Data collection, Investigation, Methodology. Guiping Liao, Xiaolin Yin, Writing- review \u0026amp; editing. Yali Zhou: Conceptualization, project administration, Writing- review \u0026amp; editing. Xiaolin Yin provided the funding support. Yali Zhou revised the final draft. All authors reviewed and edited the final manuscript before submission.\u003c/p\u003e\n\u003cp\u003eFunding This work was supported by the Scientific Research Project of Guangxi Zhuang Autonomous Region Health Committeed [ZA20231086], the Scientific Research Fund Project of Guangzhou City Life Oasis Public Welfare Service Center[GZLZ-HEMA-008]\u003c/p\u003e\n\u003cp\u003eData availability\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003eNo datasets were generated or analysed during the current study.\u003c/p\u003e\n\u003cp\u003eEthical approval Informed consent was obtained from the patients for the publication of any potentially identifiable data included in this article.\u003c/p\u003e\n\u003cp\u003eCompeting interests The authors declare no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eOpen Access\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003eThis article is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License, which permits any non-commercial use, sharing, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if you modified the licensed material. You do not have permission under this licence to share adapted material derived from this article or parts of it. The images or other third party material in this article are included in the article\u0026rsquo;s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article\u0026rsquo;s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by-nc-nd/4.0/.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eIolascon A, Andolfo I, Russo R (2020) Congenital dyserythropoietic anemias [J]. Blood 136(11):1274\u0026ndash;1283. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttp://dio.org/10.1182/blood.2019000948\u003c/span\u003e\u003cspan address=\"http://dio.10.1182/blood.2019000948\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHeimpel H, Matuschek A, Ahmed M et al (2010) Frequency of congenital dyserythropoietic anemias in Europe [J]. Eur J Haematol 85(1):20\u0026ndash;25\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGulbis B, Eleftheriou A, Angastiniotis M et al (2010) Epidemiology of rare anaemias in Europe [J]. Adv Exp Med Biol 686:375\u0026ndash;396. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttp://dio.org/10.1007/978-90-481-9485-8_22\u003c/span\u003e\u003cspan address=\"http://dio.10.1007/978-90-481-9485-8_22\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKattamis A, Kwiatkowski JL, Aydinok Y (2022) Thalassaemia [J]. Lancet 399(10343):2310\u0026ndash;2324. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttp://dio.org/10.1016/s0140-6736(22)00536-0\u003c/span\u003e\u003cspan address=\"http://dio.10.1016/s0140-6736(22)00536-0\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLai K, Huang G, Su L et al (2017) The prevalence of thalassemia in mainland China: evidence from epidemiological surveys [J]. Sci Rep 7(1):920. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttp://dio.org/10.1038/s41598-017-00967-2\u003c/span\u003e\u003cspan address=\"http://dio.10.1038/s41598-017-00967-2\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLi XY, Lan J, Luo RG et al (2009) [Epidemiological investigation and genotype of thalassemia on middle school students in Chongzuo, Guangxi] [J]. Zhonghua Liu Xing Bing Xue Za Zhi 30(6):567\u0026ndash;570\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYang K, Ren Q, Wu Y et al (2019) A Case of Hereditary Spherocytosis Caused by a Novel Homozygous Mutation in the SPTB Gene Misdiagnosed as β-Thalassemia Intermedia Due to a KLF1 Gene Mutation [J]. Hemoglobin 43(2):140\u0026ndash;144. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttp://dio.org/10.1080/03630269.2019.1620764\u003c/span\u003e\u003cspan address=\"http://dio.10.1080/03630269.2019.1620764\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYang K, Nie W, Huang Q et al (2023) Hematopoietic cell transplantation for congenital dyserythropoietic anemia IV caused by compound heterozygous KLF1 mutations [J]. Ann Hematol 102(6):1621\u0026ndash;1624. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttp://dio.org/10.1007/s00277-023-05175-9\u003c/span\u003e\u003cspan address=\"http://dio.10.1007/s00277-023-05175-9\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLiao G, Lu TT, Wei C et al (2024) A Case of Congenital Dyserythropoietic Anemia Masked by Hemoglobin H Disease [J]. Mediterr J Hematol Infect Dis 16(1):e2024059. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttp://dio.org/10.4084/mjhid.2024.059\u003c/span\u003e\u003cspan address=\"http://dio.10.4084/mjhid.2024.059\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMarra R, Nostroso A, Rosato BE et al (2024) Unveiling the genetic landscape of suspected congenital dyserythropoietic anemia type I: A retrospective cohort study of 36 patients [J]. Am J Hematol 99(8):1511\u0026ndash;1522. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttp://dio.org/10.1002/ajh.27350\u003c/span\u003e\u003cspan address=\"http://dio.10.1002/ajh.27350\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRusso R, Gambale A, Langella C et al (2014) Retrospective cohort study of 205 cases with congenital dyserythropoietic anemia type II: definition of clinical and molecular spectrum and identification of new diagnostic scores [J]. Am J Hematol 89(10):E169\u0026ndash;175. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttp://dio.org/10.1002/ajh.23800\u003c/span\u003e\u003cspan address=\"http://dio.10.1002/ajh.23800\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDass J, Nayak AR, Puri V et al (2024) Congenital dyserythropoietic anemia in children: Case series with review of literature [J]. Pediatr Hematol Oncol J 9(2):55\u0026ndash;61. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttp://dio.org/https://doi.org/\u003c/span\u003e\u003cspan address=\"http://dio.org/https://doi.org/\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.phoj.2024.02.004\u003c/span\u003e\u003cspan address=\"10.1016/j.phoj.2024.02.004\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRangarajan HG, Stanek JR, Abdel-Azim H et al (2022) Hematopoietic Cell Transplantation for Congenital Dyserythropoietic Anemia: A Report from the Pediatric Transplant and Cellular Therapy Consortium [J]. Transplantation and Cellular Therapy, 28(6): 329.\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ee321-329.e329.http://dio.org/10.1016/j.jtct.2022.03.007\u003c/span\u003e\u003cspan address=\"e321-329.e329.http://dio.10.1016/j.jtct.2022.03.007\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMiano M, Eikema DJ, Aljurf M et al (2019) Stem cell transplantation for congenital dyserythropoietic anemia: an analysis from the European Society for Blood and Marrow Transplantation [J]. Haematologica 104(8):e335\u0026ndash;e339. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttp://dio.org/10.3324/haematol.2018.206623\u003c/span\u003e\u003cspan address=\"http://dio.10.3324/haematol.2018.206623\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBraun M, W\u0026ouml;lfl M, Wiegering V et al (2014) Successful treatment of an infant with CDA type II by intrauterine transfusions and postnatal stem cell transplantation [J]. Pediatr Blood Cancer 61(4):743\u0026ndash;745. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttp://dio.org/10.1002/pbc.24786\u003c/span\u003e\u003cspan address=\"http://dio.10.1002/pbc.24786\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRemacha AF, Badell I, Pujol-Moix N et al (2002) Hydrops fetalis-associated congenital dyserythropoietic anemia treated with intrauterine transfusions and bone marrow transplantation [J]. Blood 100(1):356\u0026ndash;358. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttp://dio.org/10.1182/blood-2001-12-0351\u003c/span\u003e\u003cspan address=\"http://dio.10.1182/blood-2001-12-0351\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSpyridonidis A, Labopin M, Savani BN et al (2020) Redefining and measuring transplant conditioning intensity in current era: a study in acute myeloid leukemia patients [J]. Bone Marrow Transpl 55(6):1114\u0026ndash;1125. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttp://dio.org/10.1038/s41409-020-0803-y\u003c/span\u003e\u003cspan address=\"http://dio.10.1038/s41409-020-0803-y\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJiang J, Li X, Wu D et al (2024) Fludarabine, busulfan, and melphalan conditioning regimen in allogeneic hematopoietic stem cell transplantation for adult patients with myeloid malignancies: A multicenter retrospective study [J]. EJHaem 5(4):757\u0026ndash;767. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttp://dio.org/10.1002/jha2.947\u003c/span\u003e\u003cspan address=\"http://dio.10.1002/jha2.947\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFaulkner L, Uderzo C, Khalid S et al (2017) ATG vs thiotepa with busulfan and cyclophosphamide in matched-related bone marrow transplantation for thalassemia [J]. Blood Adv 1(13):792\u0026ndash;801. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttp://dio.org/10.1182/bloodadvances.2016004119\u003c/span\u003e\u003cspan address=\"http://dio.10.1182/bloodadvances.2016004119\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eVinchi F, Sparla R, Passos ST et al (2021) Vasculo-toxic and pro-inflammatory action of unbound haemoglobin, haem and iron in transfusion-dependent patients with haemolytic anaemias [J]. Br J Haematol 193(3):637\u0026ndash;658. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttp://dio.org/10.1111/bjh.17361\u003c/span\u003e\u003cspan address=\"http://dio.10.1111/bjh.17361\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eXiao H, Huang Q, Lai Y et al (2025) Haploidentical Hematopoietic Stem Cell Transplantation in Pediatric Transfusion-Dependent Thalassemia: A Systematic Review and Meta-Analysis [J]. Transpl Cell Ther 31(2):101e101. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e101.e112.http://dio.org/10.1016/j.jtct.2024.12.001\u003c/span\u003e\u003cspan address=\"101.e112.http://dio.10.1016/j.jtct.2024.12.001\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDul\u0026eacute;ry R, Brissot E, Mohty M (2023) Combining post-transplant cyclophosphamide with antithymocyte globulin for graft-versus-host disease prophylaxis in hematological malignancies [J]. Blood Rev 62:101080. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttp://dio.org/10.1016/j.blre.2023.101080\u003c/span\u003e\u003cspan address=\"http://dio.10.1016/j.blre.2023.101080\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLacan C, Lambert J, Forcade E et al (2024) Bone marrow graft versus peripheral blood graft in haploidentical hematopoietic stem cells transplantation: a retrospective analysis in1344 patients of SFGM-TC registry [J]. J Hematol Oncol 17(1):2. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttp://dio.org/10.1186/s13045-023-01515-4\u003c/span\u003e\u003cspan address=\"http://dio.10.1186/s13045-023-01515-4\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"annals-of-hematology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"aohe","sideBox":"Learn more about [Annals of Hematology](http://link.springer.com/journal/277)","snPcode":"277","submissionUrl":"https://submission.nature.com/new-submission/277/3","title":"Annals of Hematology","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Congenital dyserythropoietic anemia, hematopoietic stem cell transplantation, thalassemia, anti-thymocyte globulin, posttransplant cyclophosphamide","lastPublishedDoi":"10.21203/rs.3.rs-6740097/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6740097/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eCongenital dyserythropoietic anemia (CDA) comprises a heterogeneous group of rare hereditary disorders characterized by ineffective erythropoiesis and often presents with clinical features that overlap with thalassemia. Hematopoietic stem cell transplantation (HSCT) remains the only definitive curative intervention for CDA; however, experience with haploidentical HSCT in this population is limited, and the procedure is associated with considerable challenges. We report two pediatric cases of CDA coexisting with thalassemia who underwent haploidentical related donor HSCT using a novel conditioning regimen comprising three alkylating agents. This was combined with graft-versus-host disease prophylaxis utilizing posttransplant cyclophosphamide and anti-thymocyte globulin. Both patients achieved sustained engraftment, transfusion independence, and remained free of severe transplant-related complications. These cases demonstrate the feasibility and therapeutic potential of haploidentical HSCT for patients with CDA, even in the context of concomitant thalassemia.\u003c/p\u003e","manuscriptTitle":"Haploidentical Hematopoietic Stem Cell Transplantation for the Treatment of Congenital Dyserythropoietic Anemia Combined with Thalassemia: A Report of Two Cases","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-06-16 09:31:24","doi":"10.21203/rs.3.rs-6740097/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-08-04T12:30:20+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-07-25T15:00:47+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-06-19T06:37:04+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"122241430344098409046443497149418581854","date":"2025-06-14T17:46:43+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"317293405626738931496636091440840352510","date":"2025-06-11T18:47:16+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-06-11T08:02:09+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-06-02T10:44:09+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-06-02T10:42:11+00:00","index":"","fulltext":""},{"type":"submitted","content":"Annals of Hematology","date":"2025-05-24T16:14:43+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"annals-of-hematology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"aohe","sideBox":"Learn more about [Annals of Hematology](http://link.springer.com/journal/277)","snPcode":"277","submissionUrl":"https://submission.nature.com/new-submission/277/3","title":"Annals of Hematology","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"026b0379-b4b7-47a0-9613-6c076422271e","owner":[],"postedDate":"June 16th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2025-09-29T16:05:43+00:00","versionOfRecord":{"articleIdentity":"rs-6740097","link":"https://doi.org/10.1007/s00277-025-06615-4","journal":{"identity":"annals-of-hematology","isVorOnly":false,"title":"Annals of Hematology"},"publishedOn":"2025-09-26 15:57:55","publishedOnDateReadable":"September 26th, 2025"},"versionCreatedAt":"2025-06-16 09:31:24","video":"","vorDoi":"10.1007/s00277-025-06615-4","vorDoiUrl":"https://doi.org/10.1007/s00277-025-06615-4","workflowStages":[]},"version":"v1","identity":"rs-6740097","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6740097","identity":"rs-6740097","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}