Final answer:
Prion diseases are fatal neurodegenerative conditions associated with the misfolding of prion proteins, leading to diseases like Creutzfeldt-Jakob disease and mad cow disease. No cure exists, and affected individuals suffer from severe neurological symptoms that worsen over time.
Step-by-step explanation:
The pathologies associated with prion disease include a range of fatal neurodegenerative conditions known as transmissible spongiform encephalopathies (TSEs). The most well-known diseases caused by prions are Creutzfeldt-Jakob disease (CJD) in humans, bovine spongiform encephalopathy (BSE or mad cow disease) in cows, and scrapie in sheep. Prions are misfolded proteins that cause the normal prion protein (PrPc) in the brain to fold abnormally into the infectious form (PrPsc), leading to brain damage. This misfolding can be attributed to genetic mutations, spontaneous occurrences, or infection. As PrPsc accumulates, it forms aggregates, leading to the formation of neurofibrillary tangles and amyloid plaques, giving the brain a characteristic spongy appearance. Symptoms of prion diseases include memory loss, personality changes, uncoordinated movements, and eventually coma and death. Prion diseases are currently incurable, with medical support focused on alleviating symptoms.