Mehl. TNR + Prion Flashcards
Huntington, Friedrix, CJD
M. Autosomal dominant CAG trinucleotide repeat (TNR) expansion on chromosome 4 resulting in neurodegeneration and choreoathetosis. Dx?
Huntington
M. What is chorea?
Fast, purposeless, jerky movements;
M. Fast, purposeless, jerky movements - name?
Chorea
M. What is athetosis?
slow, writhing movements
M. athetosis = slow, writhing movements. Name?
athetosis
M. Huntington. Anticipation = disorder occurs earlier and more severe with each successive generation; caused by expansion of the TNR repeat.
.
M. Huntington. What part of brain fucked up?
USMLE likes caudate nuclei as part of the brain that’s fucked up.
M. Autosomal recessive GAA TNR disorder. Dx?
Friedreich ataxia
M. Friedreich ataxia. CP?
Causes ataxia, kyphoscoliosis, cardiomyopathy, pes cavus (high-arched feet), hammer toes, and early-onset type II diabetes.
M. Causes ataxia, kyphoscoliosis, cardiomyopathy, pes cavus (high-arched feet), hammer toes, and early-onset type II diabetes. Dx?
M. Friedreich ataxia.
M. CJD Creutzfeldt-Jacob disease. PRION DISEASE.
What is prion?
Prion disease; a prion is a misfolded protein that causes the misfolding of other proteins.
M. CJD Creutzfeldt-Jacob disease. PRION DISEASE.
CJD is abnormally folded protein within the CNS (PrPC -> PrPSC), where the former is an alfa-helix that becomes a misfolded beta-pleated sheet. Sounds absurdly pedantic, but it’s known to be asked for whatever reason.
.
M. CJD Creutzfeldt-Jacob disease. PRION DISEASE.
If the misfolded PrPSC variant of the protein comes into contact with normal PrPC variants, it causes them to misfold into additional PrPSC, with the process functioning exponentially.
.
M. CJD Creutzfeldt-Jacob disease. PRION DISEASE. CP?
Presents as neurodegeneration over weeks to months + myoclonus.
M. Presents as neurodegeneration over weeks to months + myoclonus. Dx?
CJD Creutzfeldt-Jacob disease. PRION DISEASE.
M. CJD Creutzfeldt-Jacob disease. PRION DISEASE. highest yield fact?
The myoclonus is the highest yield detail, since you will sometimes see CJD as a distractor answer, where I’ll say to the student, “The patient doesn’t have myoclonus though.”
