Phenylketonuria (PKU) is a rare newborn genetic disease that impacts between 1 in 10,000 to 1 in 20,000 people, depending on the individuals' genetic ancestry. PKU causes an amino acid-;called phenylalanine (Phe)-;to build up in the bloodstream. Uncontrolled PKU can lead to intellectual disability, psychiatric issues, and seizures. While current therapies can partially improve outcomes,