Prions A prion is an infectious protein that is misfolded. These proteins can aggregate in the brain and other neural tissue, forming amyloids. Diseases associated with prions … include bovine spongiform encephalopathy (mad cow disease), scrapie, kuru, chronic wasting disease, and Creutzfeldt-Jakob disease.Prions are still poorly understood by researchers, and prion diseases (transmissible spongiform encephalopathies) remain untreatable. prion is a misfolded protein that is considered an infectious agent because they cause properly folded proteins to convert into the misfolded, prion form.