Population Genetics Flashcards
Population eq assumptions (4)
Random mating
No migrtion
No random fluctuations in allele freq by
-natural selection, genetic drift, founder effect, bottleneck, inbreeding
No selection-all genotypes reproduce well
Natural selection
Sleection vs homozygous for specific allele due to adv for those who a re heterozygotes in a given environment
Genetic drift
non-ranom proportional distribtuion of alleles from one generation to another
founder effect
establishment of deleterious rare alley t high freq in small/isolated population derived from 1 ancestor
bottleneck
alleles at high freq in population that underwent population constriction
Subpopulation stratifcation
selective mating (marriage arrangement) increase homozygous and probability of recessive diseases
P+q=
aa=
bb=
ab=
total alleles of A
Total alleles of b
males in x linked rec traits
1
p^2
Q^2
2pq
p^2+2p
q^2+2q
dizygous for a or b, females are aa, ab, or bb
disease frequency=
q squared????
DO PROBLEM ON SLIDE 6/7/9
Consanguinous marriage increase in abnormatiliies
increase in how close you are related
-increased risk of homozygosity/increased chance of recessive disease
Huntingtons
100% penetrance but late onset
Check risk of being mutated at a given age-see if have disease since dominant-then can see if childd will possibly have it
Reproductive options if you are a carrier
No testing
testing and consult
IVF-PGD selection
CVS.Aminocentesis
Don’t have to tell patient that will havee disease-just ensure baby does not
Hemophilia A
X-linked recessive
100% penetrant in males, 10% in females
Prior probablity
Mendelian probabilties tha tmother is or not a carrier
Conditional probablity
other info in this family-such as brothers
Joint probablity
prouct of prior and conditional probablities
Posterior probablity
ratio of joint probability of one outcome to the sum of all joint probablities
Independent probe and both occur together
One event can happen 3 ways
Probability that event will happen by way 1
P1 x P2
P1 +P2+P3
P1/(P1+P2+P3)
Bayesian analysis
refines mendelaian risk
