Genetics in Psychiatry Flashcards
schizophrenia genes that involve DA
COMT, tyrosine hydroxylase, Dopamine D2 receptor, dopamine D3 receptor
what happens when you have more mutated risk genes?
more risk genes = greater risk for developing the neurological condition
what do COMT and DAR abnormalities cause?
hypofrontality.
mutations in COMT and DRD3 cause:
low dopamine
mutations in DRD2, Tyr-OH, and MAO cause:
high DA in the mesolimbic system
main genes involved in ADHD
DRD4 and DRD5!
what is the math formula for ADHD development?
genetic issues + environmental stress = ADHD
main genes involved in Major Depressive Disorder
DAT, DRD4, COMT. Dopamine problems -> SIGECAP symptoms
what is precursor to serotonin?
tryptophan
what does hyperfunctioning serotonin in limbic pathways cause?
panic, worry, obsession, depression. remember, a hyperfunctioning pathway may have poor serotonin activity!
serotonin genetics of Major Depressive Disorder
5-HT2A 102 T/C, 5-HTTLPR promoter, TPH. bad reuptake, bad receptors, bad synthesis -> bad serotonin.
what is precursor to norepinephrine?
tyrosine!
hyperfunctioning NE in the limbic pathways cause:
panic, worry, hyperarousal. fight or flight
hypofunctioning NE in frontocortico pathways cause
ADHD, depression
what do increased Ne and serotonin dysfunction lead to?
increased negative affect. depressed mood, guilt/disgust, fear/anxiety, hostility, irritability, loneliness
what do decreased NE and DA dysfunction lead to?
reduced positive affect. depressed mood, loss of happiness, loss of interest/pleasure, loss of energy/enthusiasm, decreased alertness, decreased self-confidence
COMT Met alleles
low degradation -> increased NE and anxiety in limbic areas
COMT Val alleles
high degradation -> low NE in cortex
what is interesting about women and MAO genes
some women have X inactivation and two copies of the MAO-A gene and double the MAO activity, leading to low NE and DA availability in the cortex, allowing for depression to occur.
