Psychiatric Genetics Flashcards
what method of inheritance is Huntington’s disease
autosomal dominant
what is the defect in Huntington’s disease
the huntington’s gene of Chromosome 4 codes for the huntington’s protein (expansion of the CAG triplet repeat)
how is the Huntington protein formed
CAG codes for glutamine, so more CAG repeats makes longer chains of glutamine in the protein = Huntington protein
what are the psychiatric Sx of Huntington
depression compulsions anxiety sucidality aggression blunted affect psychosis anxiety
what are the cognitive Sx of Huntington
- decline in executive function
- short and long term memory deficits
- dementia
what are the motor Sx of Huntington
writhing movements gait disturbance/trouble with balance and walking problems chewing/swallowing/speaking rigidity chorea clumsiness dystonia difficulty initiating movements/inability to walk weight loss
what is anticipation
earlier onset of a genetic condition in each generation
how does HD present and what is Mx like
Usually asymptomatic until adulthood
Slow onset neurological and psychological symptoms
Currently irreversible and unstoppable
Only symptomatic treatment is possible
what is the most common cause of dementia
Alzheimers disease
what genes are affected in early onset familial AD
mutations may be found in PSEN1, PSEN2 or APP (amyloid precursor protein)
what age to people with early onset familial AD present often at
before 65, often at 60
