Genetic risk calculation

Question 1

Autosomal dominant

Answer 1

• M and F affected equally
• Every generations
• Transmission by individuals of both sexes
• 50% risk in offspring

Question 2

Autosomal recessive

Answer 2

• M and F affected equally
• Affected individuals in single generation
• Parents can be related

Question 3

X-linked recessive

Answer 3

• Only M affected
• Transmitted through unaffected females to sons
• No M-M transmission

Question 4

X-linked dominant

Answer 4

• F>M affected
• F affected less severely
• Affected M can transmit to daughter but not son
• Rett syndrome, incontinentia pigmenti, fragile-X syndrome

Question 5

Y-linked inheritance

Answer 5

• Affected M only

- M only transmits to sons

Question 6

Mitochondrial inheritance

Answer 6

• Female transmission

- All offspring of affected females affected

Question 7

Familial hypercholesterolaemia inheritance pattern

Answer 7

Autosomal dominant

Question 8

Sx familial hypercholesterolaemia

Answer 8

Fatty skin deposits
Cholesterol build up in the eyelids
Angina
Cramping of calves when walking

Question 9

Inheritance pattern of Huntington’s

Answer 9

Autosomal dominant

Question 10

Examples of x-linked recessive diseases

Answer 10

Haemophilia A and B

Duchenne’s MD

Question 11

What is important to remember about blood type genotypes?

Answer 11

They are co-dominant - both alleles are expressed but type O is recessive - someone who is type A can be AA or AO