From Genes To Behavior

Question 1

Phenylketonuria (PKU) method of transmission

Answer 1

Is a autosomal recessive genetic disorder

Question 2

Phenylketonuria (PKU) symptoms and treatment

Answer 2

‣ Decreased metabolism of the amino acid pheylalanine (can’t break this amino acid down very easily and it builds up in the body to eventually mess with function and intellectual abilities)
‣ Intellectual disabilities
‣ Seizures
‣ Behavior problems
◦ Treatment - Diet (have to avoid phenylalanine
◦ Is an interesting long-term story

Question 3

Can Phenylketonuria (PKA) easy to find

Answer 3

Yes,

	‣ Relatively easy fix -> develop a testing program and almost all newborns in the US are tested for this. Most states mandate this including Illinois.  At its worst in the first 5 years of life

Question 4

Tay-Sachs disease mode of transmission

Answer 4

◦ Method of transmission: autosomal recessive genetic disorder
‣ Need to get the gene from both parents. If you only get it from one parent you will be a carrier of the disease. From both parents you will get it
‣ Both parents carrier - 25% child will be affected, 50% chance carrier, 25% chance unaffected

Question 5

Tay-Sachs disease symptoms and treatments (if possible)

Answer 5

‣ Death by age 5
‣ Lacking the enzyme to break down fatty substances
• End up clotting up neuron passages so that around 6 months the child starts to lose muscle tone. They go from making strides to regressing quickly
‣ Seizures
‣ “Cherry-red” spots in the eyes -> is a slow death
◦ Treatment - gene therapy. Used to be a 3year lifespan but gene therapy is improving it.
‣ Genetic counseling

Question 6

Huntington’s disease mode of transmission

Answer 6

Autosomal dominant genetic disorder
- (each individual child has a 50/50 chance of having it)

Question 7

Huntington’s disease, chorea symptoms and treatment

Answer 7

‣ Degeneration of nerve cells in the brain
‣ Movement and cognitive rigidity and impairments
‣ Typically at a young age they are really intelligent in cognitive abilities, then it tends to effect someone and take on the appearance of Parkinson’s. Is a degenerative disease that breaks down the brain
◦ Treatment: can only help symptoms not cure; you pretty much know that you will slowly die from this. (Will be in a home)
‣ Genetic counseling (down the road can be used)

Question 8

Treacher Collins Syndrome

Answer 8

◦ Results from mutations in the TCOF1 and POLR1D gene, it is considered an autosomal dominant condition

Question 9

Down’s syndrome transmission

Answer 9

‣ Trisomy 21 (translocation) (have a “third” or a portion of one, the bigger that portion is the more severs the disability will be)
‣ Maternal Age (odds of passing it increases with maternal age -> especially past 35)

Question 10

Why are women more likely to transmit Down’s Syndrome to their offspring

Answer 10

While men reproduce sperm every 72 hours, women are born with all of the eggs they will ever have
- this will mean that if a women does things to harm their body like constantly be dehydrating themselves for long periods of time it may effect their offspring.

Question 11

Treatment for down’s Syndrome

Answer 11

Down’s Syndrome is not cured but with proper education and parenting someone with DOwn’s can go on to go to college and be very successful
- however, people who mean well (parents) can also do harm

Question 12

What is a common issue with Down’s Syndrome

Answer 12

A delayed emotional response
- you may think something that was said a kid with Down’s wasn’t offended by because they are “still smiling” but they may till be processing it

Question 13

Why are genes an behavior/personality hard to study

Answer 13

‣ Likely to be normally distributed
‣ Polygenetic inheritance (many genes)
‣ Oftentimes better genetic work than psychological measurement (they were looking for the genes for intelligence, but it will be multiple genes so you may only find one or two)

Question 14

Monogenic versus Polygenic

Answer 14

Monogenic - hair line
- only two options
Polygenic - skin pigmentation
- many options (three or more)

Question 15

What percent of genes account for alcohol abuse

Answer 15

45-65% of genes account for factors that increase risk of alcohol abuse
- there are likely hundreds of different genes involved

Question 16

Adoption studies need

Answer 16

Hundreds to thousands of families for it to work

Question 17

Limitations of adoption studies

Answer 17

• closed adoptions
• open adoption and maybe one of their parents family members adopt them
• if a parent may want a child with a specific gene code
  -

Question 18

Major findings of adoption studies - IQ

Answer 18

IQ
- more like the biological mom (may depend on what life stage you test them at
- if tested at the age of five they may test most like the IQ of the adoptive mom. At around 15 years old they are more likely to have an IQ like their biological mom
- the biological environment has a large effect on this

Question 19

Major findings of adoption studies - Alcoholism

Answer 19

• lots of different genes involved (45-65%)
  
  • if alcoholism runs in the family it may be more likely to happen to you. (Alcoholism can damage families)
  • mutations happen at all times and places

Question 20

Alcoholism

Answer 20

People who can drink without getting hangovers and things like that from drinking are more likely to become an alcoholic

Question 21

Twin studies

Answer 21

• Example: more than 7,600 adult twins in Sweden
◦ Types of twins
‣ Monozygotic (identical twins)
‣ Dizygotic (fraternal; not identical twins)
◦ Assumptions of this method
‣ Fraternal typically share about 50% of genes (ay share more or less), identical share 100% of genes

Question 22

twin studies
general findings - the big 5

Answer 22

shows that the major personality variables have a high heriditability component.
‣ Ie: how agreeable you are, whether you are an introvert or extrovert,

• “Behavioral genetics suggests that personality traits become more heritable over time.”

Question 23

genotype

Answer 23

actual genes

Question 24

genotype examples

Answer 24

XX - female XY - male some can be XO- genitalia are female but don’t produce
organs that can let them be fertile and have children YO - typically a automatic miscarriage
XXY - Klienfelter’s syndrome XXXY
The XY tends to create a massive wash of antigens that can hid the internal and external
genitalia. The default is that all babies will start to develop as female. Sometimes for reasons we
don’t understand we can have a XY chromosome and the mother never has the antigen wash so
sometimes the external genitalia will not be male. Then sometimes testicles can descend in
adolescence.

Question 25

phenotype

Answer 25

observable traits, can be altered by the environment

Question 26

phenotype can also

Answer 26

• can be changed by the prenatal environment for the most part. However, hair color can be
  altered by choosing to alter it and dye it. Usually we can alter out phenotype but not genotype

Question 27

plasticity

Answer 27

our brain is plastic and we can change it with experience. If we teach it new things our
brain gets bigger and stronger

Question 28

reaction range

Answer 28

intelligence; the idea is that because of our genetics and prenatal environment
there is a upper limit of what we may be.
- some may be upper range, some may be average range, some may be low range. The
environment we are each in really matters

Question 29

examples of reaction range

Answer 29

• if the person is in an environment where they are not taught, talked to, or affected they
  may have a worse range. Everybody will improve but some will be able to more than others.
  her belated husband was an example of this. he was almost put into special ed, but really was
  someone who may have to look at things a bit longer than other people

Question 30

canalization

Answer 30

when we look at a species there are some things that are so important of being a prat
of that species that they are so built into our species as we develop, that it is really hard to mess up.
* things we expect to see in all members of a species
canals - used to get water to keep going through and traveling. This was made so that the
canal is really deep, making it so that it is hard to disrupt and for a canal to dry out.

Question 31

example of canalization

Answer 31

a child’s open mouth being about 12 inches from the face. When the baby hears the
sounds, sees them, the eyes watch the mouth and their mouth tries to mouth the words out. This is highly canalized, we do not teach infants to do this. When a child doesn’t do this is when people worry.
we know that they do this because mirror neurons in the brain are responding

Question 32

behavioral epigenetics

Answer 32

the study of how signals from the environment trigger molecular biological
changes that modify what goes on in brain cells.

Question 33

breast cancer in behavior

Answer 33

there is a genetic component, however not everyone will end up with
breast cancer without the environmental component that is probably unknown.

Question 34

schizophrenia in behavior

Answer 34

you cannot end up with it unless you have the genes for it. Without the
gene you won’t get it and just because you do have the genes does not necessarily
mean you will develop it
* You will have to have a inherited predisposition or vulnerability and a environmental
stressor (prenatal trauma, childhood sexual or physical abuse, family conflict,
significant life changes)
* The less the diathesis, the less stress necessary to produce the disorder

Question 35

why can’t we account for the variability not accounted for by genes

Answer 35

• most behavioral traits are about 50% genetic
• most environmental factors only minimally explain the rest of the variability
• what accounts for the rest?

Question 36

Robert Plomin

Answer 36

non-shared environments
* measuring environmental influences
◦Shared - demographic factors
◦Non-shared - varies within and between families

Question 37

Sandra Scarr

Answer 37

◦Passive genotype/environment interactions
* Your parents genotype and environment
◦Evocative genotype/environment interactions
* What we are born with (being able to evoke different responses by doing it)
◦Active genotype/environment interactions (niche picking)
* That as we get older we choose who we want to be with, be a part of, and do.
Finding out personality and our own tribe