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Flashcards in Genetic predisposition to cancer Deck (36)
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1

What do most cancers arise from

Genetic mutations either sporadic or inherited

2

What kind of cancer mutation is non inheritable

somatic

3

What causes germ-line mutations

Hereditary -present in egg or sperm of parents

4

What are tumours

clonal expansions

5

What are the three genetic processes associated with cancer syndromes

Oncogenes
Tumour suppressor genes
DNA damage-response genes

6

What are oncogenes

Mutated proto-oncogens that accelerate cell division

7

How many mutations are needed to active oncogenes

1

8

What is the role tumour suppressor genes

Inhibit cell growth
promote apoptosis
Cells breaks

9

When does cancer arrive with tumour suppressor genes

when both tumour suppressor genes fail

10

Where does the two hit in tumour suppressor genes occur resulting from carrier to cancer

first - germ line (carrier)
second - tumour formation

11

What do DNA damage-response genes do

The repair mechanics for DNA

12

When does cancer arrive from DNA damage-response genes

both genes fail, speeding the accumulation of mutations in other critical genes

13

Give an example of a DNA damage response gene MMR

failure to mismatch due to single base mismatches or short insertions and deletions leads to accumulation of nucleotide repeats - Microsatellite instability

14

What is the evidence that DNA damage response genes aren't working

Microsatellite instability

15

What is de novo mutations

mutations occurring in there germ line of parents with no family history of hereditary cancer

16

How do we look for inherited cancers

family history

17

What are most cancer susceptible genes

autosomal dominant with incomplete penetrance - therefore have genes but do not show the symptoms

18

What is sporadic cancer

cancer by chance

19

If tumours are heritable they are usually bilateral with increases the risk of what and why

secondary primer
because every cell carries the mutation

20

How is Retinoblastoma cancer occur

due to heritable or non heritable tumour supressor genes

21

What are the risks factors for breast cancer

Ageing
Family history
Hormones - late menopause/pill/HRT
Dietary factors
Lack of exercise

22

What is the most likely and second most likely gene to causes breast cancer and by what mutation

BRCA 1 then BRCA2
spordic

23

What is BRCA1 genes functions

Checkpoint mediator

DNA damage signalling and repair

Chromatin remodelling (inactive Xchromosome)

24

What is BRCA2s functions

DNA repair by HR (homologous recombination)

25

What else can BRCA1/2genes cause

Secondary breast cancer
Ovarian cancer
Male breast cancer

26

What cancer conditions can arise from tumour suppressor gene

Breast cancer
ovarian cancer
Retinoblastoma

27

What are the risk factors for colorectal cancer

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

28

How does Hereditary nonpolyposis colorectal cancer occur

DNA Mismatch Repair of HNPCC gene

29

what does polyposis and non polyposis mean

multiple adenomas present
No adenomas - but there is a risk of development

30

Lynch syndrome aka HNPCC is what

autosomal dominant genetic condition that has a high risk of colon cancer

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