Multifactorial Inheritance Patterns

Question 1

what do multifactorial disorders involve?

Answer 1

more than 3 genes & environmental triggers

Question 2

what is the onset period of multifactorial disorders?

Answer 2

late onset

Question 3

what are 3 examples of multifactorial disorders?

Answer 3

1. canine maligant lymphoma
2. Canine diabetes
3. osteochrondrosis

Question 4

how is canine diabetes exacerbated by?

Answer 4

pregnancy- high blood sugar

Question 5

Osteochrondrosis

Answer 5

pitted ball joint for femur/humerus

Question 6

do males or females have further threshold onset?

Answer 6

females

Question 7

why do males reach threshold faster?

Answer 7

because they grow faster

Question 8

Hip Displasia

Answer 8

shallow acetabulum

Question 9

what breeds/animals is hip displasia common to?

Answer 9

large dogs & livestock animals

Question 10

what are 3 environmental triggers for hip displasia?

Answer 10

1. rapid growth
2. dietary imbalance
3. over-excerise

Question 11

when is Epliepsy often onset?

Answer 11

3-5 years

Question 12

what breed is epliepsy most common in?

Answer 12

belgian shepherds

Question 13

what kind of trait is epliepsy?

Answer 13

polygenic

Question 14

what are 3 indicators of multifactorial inheritance?

Answer 14

1. late onset
2. sporadic occurence
3. Incidence not equal between sexes

Question 15

is multifactorial inheritance inherited?

Answer 15

no because of polygenic inheritance- lots of genes involved

Question 16

risk of recurrence

Answer 16

chance the trait will occur in another offspring

Question 17

Theoretical risk

Answer 17

for mendelian traits
- 25% recessive
- 50 % dominant

Question 18

Empiric risk

Answer 18

for multifactorial traits
- observed recurrence risk

Question 19

observed recurrence risk

Answer 19

chance disease will occur in offspring based on genetic / medical background

Question 20

what is the average multifactorial risk?

Answer 20

3-5%

Question 21

what is the calculated risk?

Answer 21

square root of incidence

Question 22

risk of recurrence increases exponentially for every…

Answer 22

immediate relatives

Question 23

consanguineous

Answer 23

inbreeding causes genetic traits to be stronger

Question 24

burden of the disease

Answer 24

things to be considered when breeding an animal

Question 25

breeding decisions must weigh ( ) vs ( )

Answer 25

risk & burden

Question 26

3 goals of future breeding programs

Answer 26

1. fewer antibiotics
2. greater longevity
3. increased quality of life/health

Question 27

what are 3 perceptions to burden of the disease

Answer 27

1. severity of symptoms
2. cost of treatment
3. pain/discomfort