From Genes To Behavior Flashcards
Phenylketonuria (PKU) method of transmission
Is a autosomal recessive genetic disorder
Phenylketonuria (PKU) symptoms and treatment
‣ 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
Can Phenylketonuria (PKA) easy to find
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
Tay-Sachs disease mode of transmission
◦ 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
Tay-Sachs disease symptoms and treatments (if possible)
‣ 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
Huntington’s disease mode of transmission
Autosomal dominant genetic disorder
- (each individual child has a 50/50 chance of having it)
Huntington’s disease, chorea symptoms and treatment
‣ 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)
Treacher Collins Syndrome
◦ Results from mutations in the TCOF1 and POLR1D gene, it is considered an autosomal dominant condition
Down’s syndrome transmission
‣ 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)
Why are women more likely to transmit Down’s Syndrome to their offspring
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.
Treatment for down’s Syndrome
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
What is a common issue with Down’s Syndrome
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
Why are genes an behavior/personality hard to study
‣ 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)
Monogenic versus Polygenic
Monogenic - hair line
- only two options
Polygenic - skin pigmentation
- many options (three or more)
What percent of genes account for alcohol abuse
45-65% of genes account for factors that increase risk of alcohol abuse
- there are likely hundreds of different genes involved
Adoption studies need
Hundreds to thousands of families for it to work
Limitations of adoption studies
- 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
-
Major findings of adoption studies - IQ
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
Major findings of adoption studies - Alcoholism
- 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
Alcoholism
People who can drink without getting hangovers and things like that from drinking are more likely to become an alcoholic
Twin studies
• 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
twin studies
general findings - the big 5
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.”
genotype
actual genes
genotype examples
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.
