15- Pedigree Analysis

Question 1

Probability of sharing a gene:

• Siblings
• 1st Cousins
• 2nd Cousins

Answer 1

1/2, 1/8, 1/32

Question 2

Carrier for cystic fibrosis: random and cousin with 1/8 probability of carrying gene

Answer 2

1/25, 1/3

Question 3

Carrier for Galactosemia: random and cousin with 1/8 probability of carrying gene

Answer 3

1/170, 1/21

Question 4

• Several affected males, all related through females is indicative of

Answer 4

x-linked recessive disorder

Question 5

Give 4 characteristics of an X-linked dominant disorder

Answer 5

Males will be more clinically affected
Females- having a good gene will not be as severely affected
Can’t get father son transmission
All daughters will be affected

Question 6

Several affected males, all related through females (passage through the female line

Answer 6

x-linked recessive

Question 7

square

Answer 7

male

Question 8

circle

Answer 8

female

Question 9

diamond

Answer 9

unknown

Question 10

number inside square/circle

Answer 10

number sons/daughters

Question 11

double line

Answer 11

consanguinity

Question 12

v with cross bar

Answer 12

identical twins

Question 13

v without a cross bar

Answer 13

fraternal twins

Question 14

Name three autosomal dominant diseases

Answer 14

Retinoblastoma
Achnodroplasia
Postaxial Polydactyly

Question 15

What % of offspring affected in AD diseases

Answer 15

50%

Question 16

Name 3 AR diseases

Answer 16

Cystic Fibrosis
Albinism
Galactosemia

Question 17

What % of offspring will be affected in AR diseases

Answer 17

25%