The purpose of the study is to determine whether HG004 as gene therapy is safe and effective for the treatment of Leber Congenital Amaurosis caused by mutationsin RPE65 gene.

Inclusion Criteria:

• Male or females between 8 and 50 years of age at the time of signing theinformed consent form.
• Willing to adhere to protocol as evidenced by written informed consent orparental permission and subject assent.
• Clinical confirmed diagnosis of Leber congenital amaurosis (LCA) andmolecular diagnosis of LCA due to RPE65 mutations.
• Ability to perform tests of visual and retinal function.
• Visual acuity of ≤ 20/160 or visual field less than 20 degrees in the eye to beinjected.
• Acceptable hematology, clinical chemistry, and urine laboratory parameters.

Exclusion Criteria:

• OCT examination determined that the outer nuclear layer was not visible inthe planned injection area (Bleb) in the study eye.
• Presence of epiretinal membrane by OCT.
• Complicating systemic diseases or clinically significant abnormal baselinelaboratory values.
• Complicating systemic diseases would include those in which the diseaseitself, or the treatment for the disease, can alter ocular function.
• Prior ocular surgery within six months.
• Prior gene therapy or oligonucleotide therapy treatments.
• Any other condition that would not allow the potential subject to completefollow-up examinations during the study and would, in the opinion of theinvestigator, make the potential subject unsuitable for the study.