Psychiatric Genetics

Question 1

psychiatric symptoms of huntingtons?

Answer 1

depression and/or anxiety can be first signs
can have psychosis
compulsions
suicidality
aggression
blunted affect

Question 2

cognitive features of huntingtons?

Answer 2

decline in executive function
short and long term memory deficits
dementia - global decline in global cognition

Question 3

what is executive function?

Answer 3

planning
abstract thinking
cognitive flexibility
inhibitions
adherence to rules
communication
primarily frontal lobes but whole brain involved

Question 4

motor features of huntingtons?

Answer 4

choreiform movements (brief, irregular, non-repetitive movements)
writhing movements
gait disturbance
problems chewing/swallowing/speaking
rigidity
all actions requiring muscle control eventually become impaired

Question 5

genetics of huntingtons?

Answer 5

expansion of the CAG repeat sequence in the huntington gene
more than 35 CAG repeats
CAG codes for glutamine, too many glutamine makes huntingtin protein, toxic protein crystalises out of the cell and the cell dies (neuronal loss)

Question 6

what is anticipation?

Answer 6

where disease onset is at a younger age with each generation
more repeats of CAG through generations which causes earlier onset
to do with miosis in males

Question 7

potential huntingtons treatment?

Answer 7

intra thecal treatment which targets mRNA

stops RNA being turned into protein, haulting production of huntingtin protein

Question 8

prominent symptoms of alzheimers?

Answer 8

short term memory dysfunction
dysphasia
dyspraxia
agnosia
can have mood symptoms, psychosis, behavioural change and cognitive decline

Question 9

what causes alzheimers disease?

Answer 9

formation of extracellular amyloid plaques which cause inflammation and neurofibrillary tangles inside the cells
tau protein involved in the microtubules is hyperphosphorylated and causes the tangles

Question 10

first signs of alzheimers on imaging?

Answer 10

medial temporal lobe atrophy (main sign)
hippocampus shrinking
shrinking of central cortex causes ventricles to expand

Question 11

features of familial forms of dementia?

Answer 11

more relatives affected
relatives are affected at a younger age
unusual or atypical features
tend to have 3 family members affected under 60

Question 12

is there a genetic component to bipolar?

Answer 12

yes

not a specific gene, but 57% recurrence seen if monozygotic twin is affected