What causes Creutzfeldt-Jakob disease?

Answer 1

All forms of CJD are caused by the presence of a faulty protein in the brain, called prion. Prions occur in both a normal form, which is a harmless protein found in the body's cells, and in an infectious form, which causes disease.

Answer 2

The causative agent of Creutzfeldt-Jakob disease is the CJD prion (proteinaceous infectous particle). It is neither virus, bacteria, protozoan or fungi. In fact, it is not living. It is a mutated protein, an unfolded alpha-helix into a beta-pleated sheet.

Answer 3

A prion: An external prion is the most common cause (~90%) with the remaining known cause to be a genetic mutation that causes this same prion (from an internal source rather than external).