It is thus possible that IAV/WSN infection could induce the conversion of PrPC into PrPSc in a hit-and-run manner, and the nascent PrPSc could polymerize to form the PrPSc seeds, enabling the constitutive conversion of PrPC into PrPSc in the seeded-polymerization mechanism. Here, PRNP is linked to early-onset parkinsonism-intellectual disability syndrome.