Lecture 11 (Fragile X)

Question 1

Why is it called Fragile X?

Answer 1

Because one or both of the arms of the X chromosome are bent/broken

Question 2

What kind of syndrome is Fragile X?

Answer 2

inherited

Question 3

What is the leading inherited cause of Autism?

Answer 3

Fragile X

Question 4

What are the physical abnormalities associated with Fragile X?

Answer 4

1. Long Faces,
2. Large Foreheads
3. Large Ears
4. Double Jointed

Question 5

What is the risk to male offspring of an unaffected individual carrying the Fragile X gene? what is the risk to female offspring?

Answer 5

Male: risk = 38%
Female: risk = 16%

Question 6

Why are Male more at risk for inheriting Fragile X than Females?

Answer 6

Because Females carry two copies of the X chromosome and Males only have 1

Question 7

What does Anticipation mean when talking about Fragile X?

Answer 7

It means that subsequent generations it’s more likely for fragile X symptoms to appear and more likely for them to be severe

Question 8

What year was the Fragile X gene isolated? What is it called?

Answer 8

1991

FMR-1 gene

Question 9

What does Fragile X have in common with Huntington’s?

Answer 9

It is a repeat nucleotide sequence. Excessive repeats increase chances of damaging the X chromosome.
More than 55 copies = Fragile X

Question 10

What was Robert Tryon’s 1940 Study on Rats?

Answer 10

He tried to breed rats for intelligence by selectively breeding rats who did well in a maze together and those who did poorly together for 17 generations.

Question 11

What was the problem with Tryon’s selective breeding rat study?

Answer 11

He thought he was breeding for intelligence but another psychologist tested his intelligent and dumb rats in the same maze but submerged in water and suddenly the “dumb” rats became very good and the “intelligent” rats did poorly.

What he was selecting for probably wasn’t intelligence

Question 12

What are the unintended consequences of selective breeding called? What is an example?

Answer 12

Pleiotropy
Ex: Silver foxes being bread to be more docile and manageable ended up also displaying all kinds of physical characteristics: curly tails, fluffy ears, smaller scull, smaller jaws/teeth, less stress hormone

Question 13

What accounted for the difference in which strain of rats was labeled more aggressive?

Answer 13

Ginsberg: Handled them gently
Scott: Handled them roughly

Question 14

What are Rats that are sensitive to Salt called?
What happened when they were put in a conflict/stress situation?
What does this suggest?

Answer 14

Dhal rats
They reacted as if they had consumed salt: High Blood Pressure, some died
We can be genetically vulnerable to one thing and vulnerable to something completely different

Question 15

What was the risk factor for criminality in children in unstable homes?

Answer 15

birth problems

Question 16

What is MAOA?

Answer 16

it’s an enzyme involved in the metabolism of dopamine norepinephrine

Question 17

What does Low MAOA activity put you at risk for? under what conditions?

Answer 17

Low MAOA makes it more likely to be diagnosed with Antisocial and conduct disorder if there is childhood maltreatment

Question 18

What variations of the serotonin transporter gene are there? How are they related to risk of depression?

Answer 18

two short forms
two long forms
one short and one long

If you have two short forms of the allele and you’re in a family with severe maltreatment you have a much higher risk of major depressive disorder (same thing shown for negative/stressful life events)

one short and one long also at risk
two long = not at risk

Question 19

What is the COMT gene? What are it’s variations?

How does cannabis use affect these variations?

Answer 19

Involved in the breakdown of dopamine
Gene that is related to schizophrenia
Variations:
Met/Met 
Val/Val
Val/Met

smoking cannabis as a teenager increases your risk for schizophrenia if you have the Val/Val allelic variation

Question 20

What is typology?

Answer 20

study of type & symbols

Question 21

What did Sheldon believe about genes and body type? What are the 3 types?

Answer 21

he believed genes affect body type and body type controls personality

1. Endomorphs: a person who has excess fat/round people
2. Mesomorph: excess of muscle and bone
3. Ectomorph: excess of nerve tissue, tall/thin

Question 22

What 3 personality types are there according to Sheldon? Which body types are they associated with?

Answer 22

1. Viserotonic: social, outgoing, relaxed
   = endomorphic
2. Somatotonic: Athletic, Aggressive
   =mesomorphic
3. Cerebratonic: Intelectual, sensitive, inhibited
   =ectomorphic

Question 23

What kinds of correlations did Sheldon find? What can we take from this?

Answer 23

He found high correlations
There are a lot of self fulfilling prophecies: our body predicts the way we are treated in our environment which predicts our bodies

Question 24

Why study Biochemistry?

Answer 24

1. Functional genetics
2. Chemical anatomy of the Brain
3. Pharmacology

Question 25

What are the five stages at the synapse?

Answer 25

1. Synthesis
2. Storage
3. Release
4. Degradation
5. Uptake

Question 26

What are 2 kinds of animal studies?

Answer 26

knock out studies

slective breeding

Question 27

Typology: what are imbalances of humors?

Answer 27

Sanguine: excess blood (today, cheerful)
Phlegmatic: excess phlegm (today, apathetic)
Choleric: excess yellow bile (today, angry)
Melancholic: excess black bile