Psychiatric Genetics Flashcards
psychiatric symptoms of Huntington’s disease
Depression Anxiety Compulsions Psychosis Blunted affect Aggression Suicidality
Cognitive symptoms of Huntington’s disease
Decline in executive function
Short and long term memory deficits
Dementia - progressive decline in global cognition
Motor symptoms of Huntington’s disease
Chorea Writhing movements Gait disturbance Rigidity Chewing/swallowing/speaking problems actions requiring control are impaired
What is the genetic mutation in Huntington’s
CAG repeat encoding poly-glutamine
has a toxic effect on cells causing neuronal loss and Huntington’s disease
how is age of onset determined in Huntington’s disease
by how many CAG repeats there are
More repeats = younger age of onset
how many CAG repeats are needed to develop Huntington’s disease
36 or more
v easy genetic testing available to predict whether someone will progress to Huntington’s
What is dementia
a progressive decline in global cognitive ability
what is the most common cause of dementia
Alzheimer’s disease
what is the life expectancy after a diagnosis of dementia
7 years
what is the neuropathology in Alzheimers
formation of extracellular amyloid plaques
this causes inflammation and neurofibrillary tangles
ventricles become severely enlarged
severe shrinking of the hippocampus
extreme shrinkage of cerebral cortex
what is the familial pattern in Alzheimers dementia
More relatives are affected (if a first degree relative is affected risk is 25%)
Relatives are affected at a younger age
Unusual or atypical features
what are the main factors contributing to Alzheimer’s
Genes
Environment
what genes can have mutations in early onset familial Alzheimers
PSEN1, PSEN2 or APP
tend to have 3 ppl affected in family <60
is bipolar disorder genetic
YES
recurrence in dizygotic twins - 14%
recurrence in monozygotic twins - 57%
