The one-time gene therapy is the first approved therapy designed to address the underlying cause of Glycogen Storage Disease Type Ia (GSDIa), with a list price in the United States of approximately $2.7 million per patient. Ultragenyx estimates that approximately 1,500 to 2,500 patients in the U.S. are affected by GSDIa. The therapy is expected to be available through qualified treatment centers within 30 to 60 days. In the Phase III clinical trial, Genglycos significantly reduced patients' daily cornstarch intake while maintaining glycemic control.