Lentiviral Hematopoietic Stem Cell Gene Therapy for MLD

This is a Phase I/II clinical trial of gene therapy for treating Metachromatic leukodystrophy (MLD) using a safety and efficacy improved self-inactivating lentiviral vector TYF-ARSA to transduce patient-derived hematopoietic stem cells (HSCs), with the goal of achieving therapeutic gene correction through transplantation of genetically modified HSCs. The primary objectives are to evaluate the safety and efficacy of the gene therapy clinical protocol.

Inclusion Criteria: 1. age \>= 1 month 2. ARSA gene sequence analysis to confirm MLD mutations 3. Brain MR Imaging 4. Parent / guardian / patient signing informed consent 5. Patients and their families have a strong willingness to participate in clinical trials, are willing to bear all the consequences caused by the failure of the trial, and sign the informed consent Exclusion Criteria: 1. HIV positive 2. Experiencing uncontrolled viral, bacterial or fungal infections, malignant tumors, heart abnormalities, liver dysfunction, or renal insufficiency 3. Cannot perform an MRI 4. Infection or dermatosis at infusion site 5. Any condition that may increase the subject's risk or interfere with the results of the trial, e.g. in addition to MLD, there are other neurological disorders.