Final answer:
Sporadic Creutzfeldt-Jakob Disease is mainly caused by the spontaneous misfolding of normal brain proteins into abnormal prions, with no identifiable cause in most cases. It can also be contracted through exposure to infected brain tissue, medical procedures using contaminated equipment, and genetic mutations.
Step-by-step explanation:
Causes of Sporadic Creutzfeldt-Jakob Disease (CJD)
Sporadic CJD, a fatal neurodegenerative disorder, is predominantly caused by the spontaneous misfolding of a normal brain protein into an abnormal form known as a prion. This misfolding process is not well understood, but it leads to the accumulation of these faulty proteins, ultimately causing brain damage. While most CJD cases are sporadic with no identifiable cause, others have been linked to exposure to contaminated brain or nervous system tissue. Examples include the consumption of meat from infected animals, transmission via contaminated medical equipment, and cornea or growth-hormone transplants from donors who had CJD. There are also hereditary forms of the disease caused by specific genetic mutations. In all forms, the prion proteins, which lack genetic material and differ from typical microbes, cause exponential growth of abnormal proteins that clump together, leading to the characteristic brain damage of CJD.
In the rare instances where CJD has spread from person to person, such as through human-to-human transmission, it resulted from practices like ritualistic cannibalism, as seen in kuru, or via the use of contaminated medical equipment. However, variant CJD has been linked to exposure to bovine spongiform encephalopathy (BSE), commonly known as "mad cow disease," through the consumption of infected beef products.