Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key


Play button


Play button




Click to flip

38 Cards in this Set

  • Front
  • Back
distinguishing feature of HD
hereditary chorea
presents in adult/mid-life
congregates in families
never skips a generation

distal chorea
motor impersistence
inability to sustain a posture

very subtle

classic chorea
failure of alternating motor tasks
discoordinated mvmt/balance while walking
HD is what type of disease?
progressive neurodegenerative disorder

AD w/ anticipation, gain of fxn

Huntingtin protein has what type of penetrance?
high penetrance
if you get the gene, you will get the disease at some point in your life
age of onset

most people in mid-life (35-40)
10% present before 18

variable: 15-30yrs
Initial signs/symptoms
chorea manifesting as uncoordination
change in personality/behavior
psychiatric presentation
Later signs/symptoms

what type of dementia?
progression of earlier symptoms
dystonia, dysarthria
dementing of cognition(not like alzheimer's though)

dementia of sequencing
Age of onset is closely correlated to?
Paternal Inheritence
child w/ HD that presents before age of 18 inherited it from father
*exception: if mom was juvenile HD, child can get it from mom

50% of HD pts are 43-44
if you have HD by the age of 80
you have 100% for expression
Juvenile HD
NO chorea. have parkinsonian like stiffness
Relentlessly progressing HD
True Dementia but still NO memory impairment
Neuropathy of HD
whole brain disorder
atrophy of both hemispheres and thinning of cortex
Primary Pathology by which we Grade the disease
Degree of Caudate Atrophy

primary path in caudate/putamen
Caudate Pathology

grade HD based on curve of Caudate
normally convex, eventually becomes concave
significant cortical atrophy
Chief Projection Neuorons of Caudate/Putamen
Medium Spiny Neurons

preferentially lost in HD
sparing of Ach and small spiny neurons
Subsets of MSN
divided by NP that they contain
1. Enkephalin MSN lost FIRST in garden variety HD
2. Substance P- preserved
Indirect(+) and Direct(-) to MGP
MGP--> (-)Thalmus->Cortex
Balancing Act
b/w excitatory (indirect) and inhibitory (direct)striatal input on the MGP
Adult onset HD preferentially loses?

Juvenile onset HD?
pref loss of LGP that affects indirect pathway

may affect BOTH pathways indescrim
HD Gene Location/name
short arm of chromosome 4
expanded trinuc repeat
5' CAG toward N-term of gene
unstable from gen-to-gen
Juvenile is VERY expanded
Typical Huntington gene region

IT15 gene is in what region?
Poly-Glu, Poly-pro, Heat repeats
form protein for protein scaffolding

region of CAGs that code for polyglutamine
avg repeats
incomplete pen
penetrance threshold
avg adult HD
longest ever

range of HD pts
high 30s-80s
CAG repeat abnormality seen in other diseases
Machado-Joseph Disease, SCA2/1/3, DRPLA
ALL have AD w/ anticipation
mvmt disorders
Trinuc repeat diseases
nontrans- fragileX, myotonic dystrophy
translated- Spinobulbar muscular atrophy (kennedy), HD, DRPLA, Machado-Joseph
IT15 in HD biggest degree of instability
from father to child
can have big expansion
Hutingtin in the brain
ubiquitously expressed and in ALL tissues

controls have prot in cytoplasmic location, NOT in HD patients
actually see a dec in huntingtin in HD patients, why?
because of degen or brain mass
Normal CAG Repeats, normal Huntingtin prot fxn
1. axonal transport,
2. NT release
3. synapse formation
Gain of Function leads to...
1. abnormal inflammatory response
2. generation of cytokines
3. expression of NO
4. affect Mito, cell death
5. cleavage of polyglu snarls leading to aggregates
6. allelic induced excitotoxicity
Knock out of huntingtin prot in mice
was embryonically lethal
Internuclear inclusion(NII)
stained for Ubq, get dark spots in cuadate/putamen
time-dependent expression
use creatine/co-enz Q
to treat mito problems
boost mito fxn and delay onset

environment enrichment
reverse phenotype in animals

new toy, puzzles. Affects nerve growth factors- Neurotrophins
-delayed onset in mice
normal but mutable amt of CAG repeats

definitely have HD

x>40 repeats
confirmatory testing

predictive testing

prenatal testing
if you already have symptoms. good for children w/ sympt
NOT good for children

clinical care
treat the symptoms; mvmt disorder, psych symptoms

speech therapy
treat chorea
delicate balance. good and bad
can prevent pts from learning to accomodate to HD