Prion

Prions challenge the central dogma of molecular biology — they propagate infectious disease through protein conformation alone, without any nucleic acid. A misfolded prion protein contacts a normal version, inducing it to misfold in a chain reaction. Human prion diseases include Creutzfeldt-Jakob disease and kuru (spread through ritual cannibalism). Chronic wasting disease in deer and scrapie in sheep are animal prion diseases with significant wildlife management implications.