Genetics

Question 1

Common cancer genetic conditions

Answer 1

HNPCC/Lynch syndrome 
FAP
Li-Fraumeni Syndrome
BRCA 1 and 2
Gardners syndrome

Question 2

Inheritance of Li-Fraumeni syndrome

Answer 2

Autosomal dominant

Question 3

What is the mutation in Li-fraumeni syndrome?

Answer 3

Germline mutations to p53 tumour suppressor gene

Question 4

Features of Li-fraumeni syndrome

Answer 4

High incidence of malignancies, particularly

• sarcomas
• leukaemias

Question 5

When is li-fraumeni syndrome diagnosed?

Answer 5

Individual develops sarcoma < 45 y/o
1st degree relative diagnosed with any cancer < 45 y/o and another family member develops malignancy under < 45 y/o or sarcoma at any age

Question 6

What chromosome is BRCA 1 carried on?

Answer 6

Chromosome 17

Question 7

What chromosome is BRCA 2 carried on?

Answer 7

Chromosome 13

Question 8

Features of BRCA mutation

Answer 8

Breast cancer (60%) risk
Ovarian cancer risk
- 55% BRCA 1
- 25% BRCA 2

Question 9

What BRCA mutation is involved with what cancer in men?

Answer 9

BRCA 2 gene - prostate cancer in men

Question 10

Inheritance of lynch syndrome

Answer 10

Autosomal dominant

Question 11

Features of lynch syndrome

Answer 11

Development at young age

• colonic cancer
• endometrial cancer

Question 12

What % of individuals who have lynch syndrome get colonic and/or endometrial cancer?

Answer 12

80%

Question 13

What criteria is used to identify individuals with Lynch syndrome?

Answer 13

Amsterdam criteria

Question 14

Features of the Amsterdam criteria

Answer 14

3 or more family members with a confirmed diagnosis of CRC, one of whom is a 1st degree relative of the other 2
Two successive affected generations
One or more colon cancers diagnosed under 50 y/o
FAP been excluded

Question 15

Example of a 1st degree relative

Answer 15

Parent
Sibling
Child

Question 16

What is gardeners syndrome?

Answer 16

A form of FAP - autosomal dominant familial colorectal polyposis

Question 17

Features of gardeners syndrome

Answer 17

Multiple colonic polyps
Extra colonic diseases 
- skull osteoma
- thyroid cancer
- epidermoid cysts 
Desmoid tumours seen in 15%

Question 18

What is the genetic defect in gardeners syndrome?

Answer 18

Mutation of APC gene located on chromosome 5