Ornithine Transcarbamylase (OTC) deficiency is a genetic condition where the body cannot properly remove ammonia, a waste product. This can lead to high ammonia levels, causing serious brain damage or even death. This study looks at a new treatment called ECUR-506 for baby boys under 9 months old with severe OTC deficiency. ECUR-506 is a gene editing therapy, which means it tries to fix the faulty gene causing the disorder. It is given through an IV, which is a way to get the medicine directly into the blood. The study is open-label, so both doctors and parents know the treatment being given.

• Participants need to visit multiple study centers.
• The study involves a single dose through an IV.
• Potential risks include the general risks of gene therapy.