Genetics in Psychiatry

Question 1

schizophrenia genes that involve DA

Answer 1

COMT, tyrosine hydroxylase, Dopamine D2 receptor, dopamine D3 receptor

Question 2

what happens when you have more mutated risk genes?

Answer 2

more risk genes = greater risk for developing the neurological condition

Question 3

what do COMT and DAR abnormalities cause?

Answer 3

hypofrontality.

Question 4

mutations in COMT and DRD3 cause:

Answer 4

low dopamine

Question 5

mutations in DRD2, Tyr-OH, and MAO cause:

Answer 5

high DA in the mesolimbic system

Question 6

main genes involved in ADHD

Answer 6

DRD4 and DRD5!

Question 7

what is the math formula for ADHD development?

Answer 7

genetic issues + environmental stress = ADHD

Question 8

main genes involved in Major Depressive Disorder

Answer 8

DAT, DRD4, COMT. Dopamine problems -> SIGECAP symptoms

Question 9

what is precursor to serotonin?

Answer 9

tryptophan

Question 10

what does hyperfunctioning serotonin in limbic pathways cause?

Answer 10

panic, worry, obsession, depression. remember, a hyperfunctioning pathway may have poor serotonin activity!

Question 11

serotonin genetics of Major Depressive Disorder

Answer 11

5-HT2A 102 T/C, 5-HTTLPR promoter, TPH. bad reuptake, bad receptors, bad synthesis -> bad serotonin.

Question 12

what is precursor to norepinephrine?

Answer 12

tyrosine!

Question 13

hyperfunctioning NE in the limbic pathways cause:

Answer 13

panic, worry, hyperarousal. fight or flight

Question 14

hypofunctioning NE in frontocortico pathways cause

Answer 14

ADHD, depression

Question 15

what do increased Ne and serotonin dysfunction lead to?

Answer 15

increased negative affect. depressed mood, guilt/disgust, fear/anxiety, hostility, irritability, loneliness

Question 16

what do decreased NE and DA dysfunction lead to?

Answer 16

reduced positive affect. depressed mood, loss of happiness, loss of interest/pleasure, loss of energy/enthusiasm, decreased alertness, decreased self-confidence

Question 17

COMT Met alleles

Answer 17

low degradation -> increased NE and anxiety in limbic areas

Question 18

COMT Val alleles

Answer 18

high degradation -> low NE in cortex

Question 19

what is interesting about women and MAO genes

Answer 19

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.