Genetic Predisposition to cancer Flashcards Preview

Principles of Disease > Genetic Predisposition to cancer > Flashcards

Flashcards in Genetic Predisposition to cancer Deck (56)
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1

Where do somatic mutations occur

In non-germline tissues so are non-heritable

2

Where are germline mutations found

In eggs or sperm so they are heritable and can cause cancer family syndromes

3

Which genetic processes are associated with cancer

Oncogenes
Tumour suppressor genes
DNA damage-response genes

4

What are tumours considered to be

Clonal expansions

5

What are proto-oncogenes

A normal gene that codes for proteins to regulate cell growth and differentiation

6

What can cause a proto-oncogene to become an oncogene

Mutations

7

What does one mutation in an oncogene do

Accelerate cell division

8

What are tumour suppressor genes

The cell’s brakes for cell growth

9

What are benign tumours

Tumours which are unable to metastasise
They rarely or never become cancerous but can still cause negative health effects due to pressure on other organs

10

What are the risk factors for breast cancer

Nulliparity
Estrogen use
Dietary factors (e.g. alcohol)
Lack of exercise
Ageing
Family history
Early menarche
Late menopause

11

Which genes can cause hereditary cancer

BRCA1
BRCA2
TP53
PTEN

12

What are the risk factors of colorectal cancer

Ageing
Personal history of CRC or adenomas
High-fat, low-fibre diet
Inflammatory bowel disease
Family history of CRC

13

What are adenomas seen as in colorectal cancer

Dysplastic

14

Which genes are associated with cancer

Oncogenes
Tumour suppressor genes
DNA damage-response genes

15

How many mutations are required in an oncogene for cancer development

1

16

How do tumour supressor genes act as a cell's brakes

They inhibt the cell cycle or promote apoptosis or both

17

When does cancer arise in regards to tumour supressor genes

When BOTH breaks fail

18

How many mutations are required in tumour supressor genes for cancer development

2

19

What are DNA damage response genes

The repair mechanics for DNA

20

How many mutations are required in DNA damage response genes for cancer development

2

21

What happens when both genes fail in DNA damage response genes

It speeds the accumulation of mutations in other critical genes

22

What is HNPCC

Hereditary nonpolyposis colorectal cancer

23

How does HNPCC arise

From the failure of mismatch repair (MMR) genes
So a base pair mismatch will not undergo DNA repair causing another base to be inserted (so 2 wrong bases present)

24

What does mismatch repair failure lead to

Microsatellite instability (MSI)

25

What occurs in microsatellite instability (MSI)

Novel Microsatellite fragments (simple sequence repeats - SSRs) are created

26

What do mismatch repair (MMR) genes do

Correct errors that spontaneously occur during DNA replication like single base mismatches or short insertions and deletions

27

What is phenotypic evidence that MMR is not functioning normally

The presence of MSI

28

What are dysplastic cells

Cells that show abnormalities of appearance & cell maturation
The are benign but could progress to malignancy so are known as pre-malignat

29

What are malignant tumours

Tumours which can metastasise

30

Give an example of an oncogene

RET