Estimating risk of inherited genetic disease

Question 1

Fitness

Answer 1

Relative ability of organisms to survive (long enough) to pass on their genes

Question 2

Mutation is recessive genes rarely_____

Answer 2

affect carriers

Question 3

Mutations in dominant and X-linked genes can be

Answer 3

Inherited or de novo

Question 4

Hardy-Weinberg equilibrium (HWE)

Answer 4

Allele frequencies remain constant generation to generation

Relative proportion of genotype frequencies remain constant generation to generation

Question 5

Assumptions underlying HWE

Answer 5

Mutation can be ignored
Migration is negligible
Mating is random
No selective pressure
Large population size
Allele frequency are equal in both sexes

Question 6

Founder effects

Answer 6

Physical or cultural isolation

Question 7

Define founder effect

Answer 7

the reduction in genetic variation that results when a small subset of a large population used to establish a new colony

Question 8

Genetic Drift

Answer 8

Random fluctuation of one allele transmitted to a high proportion of offspring by chance

Question 9

Bottleneck

Answer 9

Reduction of genetic diversity through an event

Question 10

Applications of HWE

Answer 10

Useful for calculating risk in genetic counselling

Useful for planning population based carrier screening programmes

Question 11

How do you determine carrier frequency

Answer 11

Mutant allele frequency- incidence of disease q2
Square route it q
1-answer (q) = p
carrier is 2(pq)