What causes Creutzfeldt-Jakob disease?

Creutzfeldt-Jakob disease (CJD) is primarily caused by infectious agents known as prions. Prions are misfolded proteins that lead to neurodegenerative diseases. Unlike bacteria or viruses, prions do not contain nucleic acids (DNA or RNA); instead, they propagate by causing normal proteins in the brain to misfold and aggregate, leading to brain damage. This unique and abnormal folding of proteins is a hallmark of prion diseases, including CJD.

Other potential causes noted in the options—such as bacterial infections, viral infections, or genetic mutations—do not accurately describe the mechanism behind CJD. While some neurological conditions may involve viral or genetic factors, Creutzfeldt-Jakob disease is distinct in that it is specifically identified as a prion disease, with an infectious mechanism that is quite different from traditional infections. This prion-induced pathology underpins the progressive neurodegeneration and distinctive symptoms observed in individuals affected by CJD.