A gene for the normal protein (PrPC) has been identified. This has led to the hypothesis that a mutation in this gene (Prnp) somehow makes PrPC more likely to change spontaneously into the PrPRes/PrPSc prion.
Yet another hypothesis is that the prions and the spongy structures they cause are harmless, and thus what actually causes the damage is the depletion of prion proteins.
