Clinical Trial of the Dual Vector Base Editor for the Treatment of the CHD3-R1025W Mutation

To evaluate the safety, tolerability and preliminary efficacy study of a single intrathecal injection of the dual vector AAV-CHD3-R1025W base editor for the treatment of developmental disorders caused by the R1025W mutation in the CHD3 gene

Inclusion Criteria: * Clinical diagnosis of Snijders Blok-Campeau syndrome * Heterozygous mutation of c.3073C\>T, p.(Arg1025Trp) in the CHD3 gene * Normal liver, heart and immune function * Normal coagulation and platelet counts Exclusion Criteria: * Brain tumor or intracranial space-occupying lesion * Contraindications to administration of lumbar puncture or sheath injection administration * Persistent status epilepticus or recurrent epileptic control instability * Presence of unstable systemic disease including active bacterial, fungal or HIV, hepatitis A, hepatitis B infection * Serum anti-AAV neutralizing antibody titer \>1:50 (ELISA immunoassay) * Treatment with immunological agents other than protocol-specified prophylaxis within 3 months * Prior gene therapy * Participation in another clinical trial, or treatment with another investigational product within 30 days or 5 half-lives * Known allergy to any investigational product