Tianasen (ASO-GNAO1) for GNAO1-Encephalopathy With Epilepsy and Movement Disorders.

Inclusion criteria

• Informed Consent: Written informed consent from the parent(s) or legal guardian(s) of the patient and the child's assent (where applicable based on age and cognitive ability), obtained prior to the initiation of any study-related procedures.
• Age: Male or female children aged 1 year and older (≥1 year) until 14 years at the time of informed consent signing.
• Diagnosis: A confirmed a c.607G\>A variant in of GNAO1 gene based on genetic testing, and a clinical presentation that includes both epilepsy and movement disorders.
• Treatment Resistance:
• For seizures: Documented resistance to antiseizure medications prior to screening, defined as the persistence of seizures despite adequate trials of at least two appropriately dosed antiseizure medications.
• For non-epileptic hyperkinesias/dystonia: Documented resistance to anti-hyperkinetic medications prior to screening, defined as the persistence of debilitating hyperkinesias or dystonic attacks despite adequate trials of at least two appropriately dosed anti-hyperkinetic medications.
• Contraception (for females of reproductive potential): For post- menarche female adolescents, a negative serum or urine pregnancy test at screening and agreement to use highly effective methods of contraception (e.g., hormonal implants, combined oral contraceptives, intrauterine device) throughout the study participation period.

Exclusion criteria

• Unacceptable Risk: Any concurrent severe medical, neurological, or psychiatric condition, or any other significant circumstance (e.g., unstable clinical status) that, in the judgment of the Investigator, could significantly increase the risk associated with study participation or the administration of the investigational product, or could interfere with the interpretation of study results.
• Impossibility of Intervention: Any anatomical abnormality, coagulation disorder, active infection, or other condition that constitutes a contraindication to or precludes the safe performance of repeated lumbar punctures for intrathecal administration of the study drug.
• Pregnancy or Lactation: Pregnancy, lactation, or intention to become pregnant during the study period.
• Concurrent Experimental Therapy: Receipt of any other investigational drug, device, or biological product within 1 month prior to screening or within a period of at least 5 half-lives of that product (whichever is longer).
• Protocol Compliance: Any other disease, condition, or behavioral factor that, in the opinion of the Investigator, could compromise the patient's safety, preclude adherence to the protocol schedule, or interfere with the study conduct and endpoint assessments. Age: 14 years and older