Prions Flashcards
What is a prion?
A prion is an infectious protein particle that is not a living organism but can be transmitted like infectious agents such as viruses.
Who discovered prions, and what was the first prion disease identified?
Stanley Prusiner’s research team in the 1980s discovered prions, with scrapie in sheep being the first identified prion disease.
What are the three forms of prion-associated disease in humans?
Familial, Sporadic, and Transmissible.
How do prions cause disease?
The disease-causing prion (PrP-res) misfolds normal prion proteins (PrP-sen), leading to their accumulation, forming amyloid fibres that are toxic to nerve cells.
Prions lack
genetic material.
PrP-res is resistant to degradation, leading to
accumulation and disease progression.
Prion diseases are fatal and currently have
no cure.
BSE (Mad Cow Disease) affects cattle and has a long incubation period
(4-6 years).
Creutzfeldt-Jakob Disease (CJD) can occur sporadically, be inherited, or be acquired through consumption of
contaminated food.
Prions can be destroyed using standard sterilization methods.
False – Prions are highly resistant to heat and chemical disinfectants.
Prion diseases primarily affect the nervous system.
True – Prion diseases lead to neurodegeneration, causing progressive neurological symptoms.
Variant CJD (vCJD) is acquired through spontaneous mutations.
False – vCJD is acquired through consuming prion-contaminated animal products.
PrP-sen and PrP-res have the same amino acid sequence.
True – They differ in their folding, not their sequence.
The presence of prions in the brain leads to the formation of __________, which are toxic to neurons.
Amyloid fibres
The abnormal prion protein is referred to as __________ because it is resistant to degradation.
PrP-res.
Prion diseases fall under the category of __________, which cause sponge-like degeneration in the brain.
Transmissible Spongiform Encephalopathies (TSEs).
The mutation at codon __________ in the prion protein gene is associated with increased susceptibility to vCJD.
129
What is the key distinguishing feature of prions compared to viruses and bacteria?
A) Prions contain RNA but no DNA
B) Prions are made entirely of protein with no genetic material
C) Prions contain both DNA and RNA but lack a cell wall
D) Prions are bacterial spores that resist antibiotics
A: B) Prions are made entirely of protein with no genetic material.
Which of the following prion diseases affects sheep?
A) Chronic Wasting Disease
B) Scrapie
C) Creutzfeldt-Jakob Disease
D) Gerstmann-Sträussler-Scheinker Syndrome
A: B) Scrapie.
Which of the following is the primary method of diagnosing CJD?
A) Blood test
B) Presence of the 14-3-3 protein in cerebrospinal fluid
C) Urinalysis
D) Genetic sequencing of bacterial DNA
A: B) Presence of the 14-3-3 protein in cerebrospinal fluid.
Which of the following prion diseases is associated with inherited mutations?
A) Sporadic CJD
B) Variant CJD
C) Familial CJD
D) Kuru
A: C) Familial CJD.
A 62-year-old patient presents with rapidly progressive dementia, cerebellar dysfunction, and myoclonus. Brain imaging shows spongiform changes, and cerebrospinal fluid analysis detects the 14-3-3 protein. What is the most likely diagnosis?
A: Sporadic Creutzfeldt-Jakob Disease (sCJD).
A farmer notices that several of his sheep exhibit intense itching, excessive wool loss, and uncoordinated movement. Based on these symptoms, what prion disease is most likely affecting his flock?
A: Scrapie.
A previously healthy young adult develops psychiatric symptoms followed by loss of coordination and dementia over several months. The patient recently traveled to a region with past BSE outbreaks. What is the most likely prion disease?
A: Variant Creutzfeldt-Jakob Disease (vCJD).
