Genetic Risk Analysis

Question 1

Principle of Segregation

Answer 1

. Sexually reproducing organisms have genes that occur in pairs
. Only one of the pair transmit to offspring

Question 2

Principle of independent assortment

Answer 2

. Genes at different loci are transmitted independently

. Doesn’t hold in cases where genes are located in close proximity to each other on same chromosome

Question 3

Multiplication rule of probability

Answer 3

. If 2 trials are independent of one another then the probability of obtaining a given outcome in both trials is the product of probabilities of each outcome

Question 4

Addition rule of probability

Answer 4

. To know the probability of either one outcome OR another the probabilities can be added together

Question 5

Cystic fibrosis

Answer 5

. Most common severe autosomal recessive disease in USA (1/3300 total, 1/2500 whites)
. Accumulation of thick mucus in lungs and pancreas leading to pneumonia and malabsorption
. 85% both pulmonary and pancreatic disease, 15% only pulmonary
. Survival age ~47

Question 6

CFTR gene

Answer 6

. Codes for transmembrane regulator of Cl channel
. 100s of mutations, 25 most common
. Gene sequencing done for individuals that have family history of specific mutation

Question 7

Hardy Weinberg principle

Answer 7

. Relationship btw gene frequency and genotype frequency
. Used then 1 or more alleles produces recessive trait in population that meets specific requirements
.p= dominant, q=negative
.p+q=1.0
.p^2 + 2pq + q^2 = 1

Question 8

Population requirements for Hardy Weinberg

Answer 8

. Large
. No natural selection for or against any genotype
. Random mating w/ respect of genotype of interest
. Negligible rate of new mutations