Inclusion Criteria: Inclusion Criteria For MLD: 1. Confirmed diagnosis as MLD by ARSA genetic diagnosis, MRI（Magnetic Resonance Imaging）and low ARSA A activity (below 20% of normal level); 2. The patient' symptoms and lesions have not been developed to the end stage of MLD. 3. age \< 16.0 years at symptom onset Inclusion Criteria For ALD: 1. Confirmed diagnosis as ALD by ABCD1 genetic diagnosis, abnormal MRI imaging, abnormal high level of very long chain fatty acid (VLCFA) and adrenocorticotropic hormone (ACTH); 2. The patient' symptoms and lesions have not been developed to the end stage of ALD. 3. age \< 16.0 years at symptom onset Exclusion Criteria: Exclusion Criteria For MLD： 1. At a pre-symptomatic stage of of MLD; 2. ARSA activity \>50% compared to healthy individuals; 3. End stage of MLD; 4. Other complications, ie. Cancer; 5. human immunodeficiency virus（HIV） RNA and/or hepatitis C virus RNA and/or hepatitis B virus DNA positive patients; 6. Patients who underwent allogenic hematopoietic stem cell transplantation with evidence of residual cells of donor origin. 7. Serious organ dysfunction; 8. were enrolled in other clinical trials in the 6 months prior to screening; 9. had any other concern that hampered the compliance or safety as judged by the investigator; 10. Adult Exclusion Criteria For ALD: 1. No evidence of brain lesions; 2. Normal level of VLCFAs in blood; 3. End stage of ALD; 4. Other complications, ie. Cancer; 5. human immunodeficiency virus（HIV） RNA and/or hepatitis C virus RNA and/or hepatitis B virus DNA positive patients; 6. Patients who underwent allogenic hematopoietic stem cell transplantation with evidence of residual cells of donor origin. 7. Serious organ dysfunction; 8. were enrolled in other clinical trials in the 6 months prior to screening; 9. had any other concern that hampered the compliance or safety as judged by the investigator; 10. Adult