Cancer genetics

Question 1

What is the two-hit hypothesis?

Answer 1

That to contribute towards cancer, tumour-suppressor genes require both alleles to be inactivated.

Question 2

What risk does a mutation in BRCA1 cause?

Answer 2

• 50-80% chance of breast cancer

- 20-50% chance of ovarian cancer

Question 3

What risk does a mutation in BRCA2 cause?

Answer 3

• 50-80% for breast cancer

- 10-20% for ovarian cancer

Question 4

What is the role of BRCA1 and BRCA2?

Answer 4

Tumour suppressor genes:

- DNA repair of double stranded breaks

Question 5

What id p53

Answer 5

Tumour suppressor gene - prevents entry to S phase of cell cycle

Question 6

Mutation in the p53 gene is associated with what?

Answer 6

Li-Fraumani Syndrome

- early onset breast cancer, sarcoma and lukeimia