Growth and Development-related Outcomes in Children With Transfusion-dependent Beta-thalassemia After Gene Therapy

Inclusion Criteria: Gene therapy group-inclusion * Male or female age of 3-14 years * TDT Children who have received gene therapy. * Subjects who are willing and able to provide written informed consent. Supportive therapy group-inclusion * Gender same as the matched case * Age similar to the matched case * Children with β-TDT * No history of gene therapy or allogeneic hematopoietic stem cell transplantation * Subjects who are willing and able to provide written informed consent. Healthy children group-inclusion * Gender same as the matched case * Age similar to the matched case * Subjects who are willing and able to provide written informed consent. Exclusion Criteria: * Diagnosis of compound α-thalassemia * Uncontrolled systemic fungal, bacterial, or viral infection * History of malignant solid tumors, myeloproliferative or immunodeficiency diseases * Diagnosed with mental illness * Patients considered to be ineligible for the study by the investigator for reasons other than the above Discontinuation of Study : * Subjects who are unwilling or unable to continue participating in the study (withdrawal of informed consent) may withdraw from the study * Subjects who received gene therapy or allogeneic hematopoietic stem cell transplantation during the study * The subject is seriously non-compliant with the study requirements, such as missing 2 consecutive visits * Subject lost to follow-up