I can't give you a source like that. From the Wikipedia article on prions, it appears that several prion-based diseases are suspected, but that so far the only proven cause for such a disease has been the "major prion protein." In 2015 a hypothesis was advanced that multiple system atrophy (Shy–Drager syndrome) was caused by a prion form of the alpha-synuclein molecule. However, if any subsequent proof has followed, neither the wikipedia pages on prions or alpha-synuclein have caught up with that.