Prion disease Flashcards
What is a Prion?
Protein - only infectious agent
essentially only contains protein, no DNA
What does prion diseasecause
transmissible spongiform encepalopathy in humans and animals
What is the action of prions on the body in sporadic CJD
they enter the brain
they trigger a cascade whereby they convert normal prions to abnormal form
This causes SPONGIFORM VACUOLISATION OF THE BRAIN
This causes rapid neurodegeneration
What codon is prion currently coded in
codon 129
What polymorphism codes for prion disease
MM
What is the protein structure of abnormal prion compared to normal
PrPsc = beta pleated sheet configuration (so cannot be broken fown by proteases or radiation)
Normal prion PrP = alpha helix, can be broken down easility
What occurs with prions in the body once you get an abnormal prion?
the abnormal prion acts as a template to convert all normal prion to abnormal
This causes rapid degeneration
What is classification of prion disease
- sporadic creutzfield jacob disease (80%)
- aquired e.g. Kuru, variant CJD , iatrogenic
- genetic
What mutation is associated to genetic prion disease
PRPN mutation
What is the presentation of sporadic. CJD
OLD people (avg 64) Rapid dementia with - myoclonus - cortical blindness - akinetic mutism - LMN signs
How do you diagnose CJD
EEG MRI (increased signal in BG) CSF Brain biopsy Histology
What is the feature of sporadic CJD in CSF
Raised 14-3-3 protein and S100
These are markers of rapid degeneration
What does brain histology for CJD show
spongiform vacuolisation
amyloid plaques
What causes variant CJD
cow meat (bovine spongiform encepalopathy)
Who did vCJD mainly affect?
YOUNG people
