inheritance and polygenetic disorders

Question 1

What are the twtypes of polygenetic disorder clasficications

Answer 1

Dicotomous : have or do not have, can have a cut off point for being deemed to have the trait

Continuous: The whole population will lie of a distribution for the trait

Question 2

How can envrionmental factors impact polygenetic disorders

Answer 2

Polygenetic disorders are impacted by both genetics and envrionmental components-
different traits are impacted at different percentages
some only effect by one or the other

Question 3

Why are polygenetic disorders very importnat to study

Answer 3

Most common type of disorder / trait
monogenetic are rare (6%)
leading cause of death in the weastern world

Question 4

What are the two key factors relating to polygenetic disorders

Answer 4

They can effect any type of protein
they can effect anywhere on a metabolic pathway

Question 5

What are two examples of metabolic pathway interuption

Answer 5

PKU = disruption at start of pathway -> all other enzymes have no substrate and connot do anything
ALDH2 = asisan flush -> last protein in pathway -> proteins beforehand still fucntion, leads to toxic metabolite buildup

Question 6

What do the study of polygenetic diseases look for and the pros and cons of these

Answer 6

Look for corrolation and association between varients in individuals who carry the phenotype of interest

Pros:
- Polygenetic traits are common -> large sample size is easy + minigation of environmental factors
Cons:
- Looking for multiple genes -> many ways to get disease
- many ways phenotype can present itself and different outcomes depending on your definition

Question 7

What is an example of a test which looks for polygenetic disorders

Answer 7

Genome wide association study:
- looks at Lagre range on SNPs and assigns them a unique association marker
- located all over genome
- Markers are cut down to a smaller number with a higher likely hood of association with the disorder

Question 8

What is cancer + how is it normally factors

Answer 8

Cancer is a group of related diseases due to uncontrolled cell growth
0- cell no longer listens to control signals about death/replication
is caused by the accumulation of somatic mutations

Factors:
- removed by immune cells
- Cannot be passed on
- higher effect in elderly due to more replications
- occurs due to failure of DNA replication or chemical exsposure

Question 9

What are proto-oncogenes

Answer 9

Protoonco genes are those which promote cell growth division and death
Mutations which upregulate these -> oncogenes -> promote the likely hodd of cancer
- Gain of function -> dominent

Question 10

What are tumor supressor genes

Answer 10

Inhibit division in cells
mutations in these lose their ability to regulate -> cancer
- loss of functionn -> recessive -> require two copys

Question 11

How do oncogenes + tumor supressor genes function to prevent cancer / how is it caused

Answer 11

Proto- oncogenes -> growth which is like gas
tumor supressors -> inhibit growth which is like gas
they can balance each other when one is mutated

If both become mutant then the cell will become a tumor