What is a common feature of all prion diseases?

• A. They are caused by genetic mutations
• B. They spread through bacteria
• C. They are caused by misfolded proteins
• D. They have a viral origin

Answer: (C)

Prion diseases are indeed characterized by being caused by misfolded proteins. These proteins, known as prions, are abnormal forms of normal cellular proteins that can induce other normal proteins to also misfold. This misfolding leads to the accumulation of abnormal proteins in the brain, resulting in neurodegenerative conditions.

These diseases are unique because they do not involve infectious agents like bacteria or viruses; rather, they spread through the misfolding of proteins and can propagate through contact with contaminated tissue or fluids. The nature of prions means that they can be quite resilient, able to withstand standard sterilization procedures that usually eliminate bacteria and viruses. Consequently, the distinctive feature of prion diseases being related to misfolded proteins sets them apart from other pathogens that typically have genetic material and a defined infectious structure.