Huntington's Disease Flashcards
What is Huntington’s disease?
Neurodegenerative disorder.
-motor, cognitive and psychiatric disturbances
How does Huntington’s affect movement?
Chorea
Dystonia
Bradykinesia
How does Huntington’s affect mood?
Depression
Anxiety
Aggression
How does Huntington’s affect cognition?
Rigidity of thought
Memory loss
Dementia
What is the mean age of onset?
35-44 years.
What is the median survival?
15-18 years after onset.
What are the genetic features?
Autosomal dominant.
- HTT gene at 4q16.3
- expansion of CAG repeats (>40)
What amino acid does CAG code for?
Glutamine.
|»_space; polyglutamine / poly Q expansion
Where does the polyQ cellular protein mainly aggregate in Huntington’s?
Basal ganglia.
-especially caudate nucleus
What is anticipation?
Onset of a disorder occurs at an earlier age in next generation.
-often more severe too
What sort of disorders in anticipation associated with?
Triple repeat disorders.
- unstable and may increase
- e.g. Huntington’s, fragile X
What is anticipation often linked to?
Gender of the parent.
- Paternal - Huntington’s
- Maternal - myotonic dystrophy, fragile X
What sort of gene test are done for people with symptoms of Huntington’s?
Diagnostic gene tests.
What sort of gene test are done for people who are asymptomatic but have FH of Huntington’s?
Predictive gene tests.
What is predictive gene testing?
Use of a genetic test in an asymptomatic person to predict future risk of disease.
