Can a One-Time gene therapy fix the root cause of rett syndrome?

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: 1. Age range from 2 to 10 years old, female; 2. The clinical diagnosis of the subject is RTT, and after genetic testing, it was found to be a pathogenic variant of the MECP2 gene; 3. The legal guardian is able to understand the requirements and procedures of the research plan, voluntarily participate, and sign an informed consent form. Exclusion Criteria: 1. Has participated in or is currently participating in other RTT drug clinical trials or other AAV gene therapy clinical studies; 2. The subject has a history of head injuries that can cause neurological disorders such as epilepsy, physical disabilities, etc; 3. The subject has MECP2 gene mutation but does not cause RTT; 4. Subjects with allergic constitution, including those allergic or hypersensitive to prednisolone, other glucocorticoids, their excipients, and local anesthetics; 5. The subjects had status epilepticus in the 3 months prior to enrollment; 6. Subjects require invasive or non-invasive ventilation support; 7. Serum anti AAV9 neutralizing antibody titer\>1:200; 8. During the screening visit, subjects with the following abnormal findings: ALT, AST, and γ-glutamyl transferase (GGT) levels all ≥1.0×ULN, TBIL ≥1.0×ULN; serum creatinine (Scr) \>1.0×ULN; activated partial thromboplastin time (APTT) prolonged \>1.5×ULN / INR \>1.5; platelet count (PLT) \<100×10\^9/L or investigator judgment that PLT results are abnormal and clinically significant; 9. Contraindications for lumbar puncture or intrathecal therapy exist; 10. Positive for human immunodeficiency virus antibody, or hepatitis B surface antigen, or hepatitis C antibody, or Treponema pallidum antibody, or current TORCH viral infection, or current Epstein-Barr virus infection; 11. Combination use of any of the following drugs within 90 days prior to administration, and planned immunotherapy therapy (cyclosporine, tacrolimus, methotrexate, cyclophosphamide, intravenous immunoglobulin, rituximab) other than prophylactic medication as specified in the protocol within 3 months after the start of the trial; 12. The researchers believe that it is not suitable to participate in this study.