What are prions known to cause?

Prions are misfolded proteins that can induce other normal proteins to misfold, leading to a cascade of harmful effects on cellular function. They are most notably associated with a group of progressive neurodegenerative diseases that affect the brain and nervous system. These include conditions such as Creutzfeldt-Jakob disease, BSE (commonly known as mad cow disease), and other spongiform encephalopathies, which are characterized by the accumulation of abnormal prion proteins in neural tissue. This accumulation results in cognitive decline, neurological symptoms, and ultimately, death.

In contrast, heart disease, muscle disorders, and digestive issues are not linked to prion activity. Heart disease typically involves issues with the cardiovascular system, muscle disorders are generally the result of genetic or acquired factors affecting muscle tissue, and digestive issues are related to the gastrointestinal system, none of which involve prion-induced pathology. Thus, the correct association of prions with brain and nerve diseases highlights their unique and detrimental role in neurodegenerative conditions.