Psychiatric Genetics Flashcards
What may be the first signs of Huntington’s disease?
Depression and anxiety
What are some psychiatric symptoms of Huntington’s disease?
Psychosis, blunted affect, aggression, suicidality, compulsions
What are the cognitive symptoms of Huntington’s disease?
Decline in executive function, short and long term memory deficits, dementia
What are the motor signs of Huntington’s disease?
Rigidity, choreiform movements, writhing movements, gait disturbances, problems chewing, swallowing or speaking
What causes Huntington’s disease?
CAG repeats = encodes polyglutamine
How does Huntington’s disease present?
Usually asymptomatic until adulthood = slow onset neurological and psychological symptoms
Can Huntington’s disease be cured?
No = irreversible and can only offer symptomatic treatment
How does Alzheimer’s disease present?
Dementia = progressive decline in cognitive ability
Short term memory dysfunction, dysphagia, dyspraxia, agnosia, mood symptoms, psychosis, behavioural disturbance
What is the life expectancy of Alzheimer’s disease?
Average of 7 years after diagnosis
Eventually require full time care = bed bound and fully dependent, lose ability to swallow
What is the pathogenesis of Alzheimer’s disease?
Involves formation of extracellular amyloid plaques (cause inflammation) and intracellular neurofibrillary tangles
How do you recognise the familial form of Alzheimer’s disease?
More relatives affected
Relatives affected at younger age
Atypical features
What is the risk of Alzheimer’s disease?
Lifetime risk is 10%
Risk is 25% if there is one affected first degree relative
How common is early onset Alzheimer’s disease?
Accounts for 2% of cases = EOFAD mutations in PSEN1, PSEN2 or APP, usually 3 affected individuals in family under age 60
How heritable is bipolar disorder?
Very = recurrence is 14% in dizygotic twins and 57% in monozygotic twins, positive family history increases risk
How do genetics help treatment of bipolar disorder?
Some evidence shows that if one family member responds to a treatment then others will benefit from the same one
