Prions Flashcards
Name for prions
Spongiform Encephalopathies
A normal prion consists of…
3 alpha helices and a beta pleated sheet
Prion diseases are caused by…
And how do prions multiply in the brain
The misfolding of the prion protein, where an alpha helix and beta pleated sheet are lost.
Diseased prion binds to a normal one, inducing a conformational change, causing disease.
Commonalities in prion diseases show…
Changes in gait (walking), activity and aggression
Transmission of prion diseases
Sporadic - random mutations
Acquired - surgical equipment, ingestion
Familial - passed down over generations
Prevention of prion diseases
Ban use of animal matter in animal feed
Ban export of meat from countries with outbreaks
Disposal of contaminated equipment
Slaughter of infected animals
Scrapie symptoms
Changes in behaviour, sheep scratch themselves against objects and bite feet/limbs
Mad cow disease symptoms
Changes in behaviour and increased aggression
Sporadic Creutzfeld-Jacob disease (CJD) causes + symptoms
Caused by a random mutation in the protein or the gene that encodes for the protein.
Normal prion PrP^C changes to PrP^SC
Gene is dominant so only needs one copy to be inherited.
Symptoms include dementia, hallucinations, depression, seizures. Mortality due to pneumonia.
Iatrogenic Creutzfeld-Jacob disease (iCJD)
Acquired from surgical treatments. High incidence in patients receiving growth hormone.
Sterilisation is equipment is ineffective as prions can withstand autoclaving.
Variant Creutzfeld-Jacob disease (variant CJD)
Caused by consumption of meat products that contain PrP^SC
Kuru was seen in a tribe which practiced cannibalism of the brain. Symptoms include…
1st stage - decreased muscle control, tremors
2nd stage - incapable of walking without support, depression, uncontrolled laughter
3rd stage - unable to speak, unresponsive, ulcerated wounds
Gerstmann-Sträussler-Scheinker (GSS)
Caused by autosomal dominant mutation of gene that codes for prion.
Symptoms include dementia, depression, speech impairment, seizures.
Fatal Familial Insomnia is an inherited disease, although it can arise spontaneously. Cause and symptoms include…
Caused by degeneration of the Thalamus (sleep cycle).
Stage 1 - panic attacks, paranoia
Stage 2 - hallucinations, sweating
Stage 3 - inability to sleep, weight loss
Stage 4 - dementia, mute, insomnia, death
