Haplo-Cord HSCT for AML/MDS

Inclusion Criteria: * Age between 14 and 60 years, with no gender restriction. * Intermediate- or high-risk AML in first complete remission (CR1). * AML in second or subsequent complete remission (≥ CR2). * Relapsed or refractory AML. * Low-risk AML meeting any of the following: Failure to achieve a ≥3-log reduction in RUNX1::RUNX1T1 transcript level compared with baseline after 2 consolidation cycles, or loss of major molecular remission (MMR) within 6 months; CBFB::MYH11/ABL ratio \> 0.1% at any time point after 2 consolidation cycles in patients with CBFB::MYH11-rearranged AML; Presence of D816 KIT mutation in patients with CBFB::MYH11-rearranged AML; Flow cytometry-positive MRD at any time point after 2 consolidation cycles in patients with CEBPA double-mutant AML; Persistently positive MRD after chemotherapy in patients with NPM1-mutated AML. * Intermediate-2 or high-risk MDS according to the IPSS scoring system. * Adequate general health status and ability to tolerate hematopoietic stem cell transplantation. * Provision of signed informed consent and willingness to comply with study-required follow-up and examinations. Exclusion Criteria: * Prior history of other hematopoietic stem cell transplantation. * History of ex vivo T-cell-depleted stem cell transplantation. * Survival duration of less than 1 month after transplantation. * Severe organ dysfunction, including significant impairment of hepatic, renal, cardiac, or pulmonary function. * Active severe infection, such as uncontrolled pneumonia, sepsis, or other systemic infections. * History of severe hypersensitivity reactions to study medications, including cyclophosphamide or anti-thymocyte globulin (ATG). * Presence of severe psychiatric disorders or cognitive impairment that precludes compliance with study treatment and follow-up. * Pregnant or lactating women. * Concurrent malignancy of other organ system. * Any other medical conditions deemed inappropriate for study participation by the treating investigators.