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Flashcards in Genetic Predisposition to Cancer Deck (52)
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1
Q

Cancer is a ______ disease of somatic cells.

A

Genetic

2
Q

Is cancer common?

A

Yes

3
Q

What are the 2 main reasons for cancer?

A

Chance

Environmental factors

4
Q

Where do somatic mutations occur?

A

Nongermline tissues

5
Q

Where are germline mutations present?

A

In egg or sperm

6
Q

What type of mutation is heritable?

A

Germline

7
Q

What do tumours begin as?

A

Mutation in one cell

8
Q

What are the 3 processes associated with cancer?

A

Oncogenes
Tumour supressor genes
DNA damage respose genes

9
Q

What do proto-oncogenes normally code for?

A

Proteins to regulate cell growth and differentiation

10
Q

What do mutations change proto-oncogenes into?

A

Oncogene

11
Q

What can oncogenes do?

A

Accelerate cell division

12
Q

What do tumour suppressor genes do?

A

Inhibit cell cell or promote apoptosis

13
Q

What do DNA damage response genes do?

A

Repair mechanics for DNA

14
Q

Why does cancer arise when both DNA damage response genes fail?

A

Speeds the accumulation of mutations in other critical genes.

15
Q

What does mismatch repair failure lead to?

A

Microsatellite instability.

16
Q

MSI is the phenotypic evidence that MMR is not ______ normally.

A

Functioning

17
Q

Define dysplastic.

A

“Benign” but could progress to malignancy.

18
Q

What is a dominantly inherited cancer syndrome by oncogenes?

A

Thyroid cancer

19
Q

What is a dominantly inherited cancer syndrome by tumour suppressor genes?

A

Breast/ovarian cancer

20
Q

What is a dominantly inherited cancer syndrome by DNA repair?

A

Lynch Syndrome

21
Q

What type of disease needs the copy from both parents?

A

Autosomal recessive

22
Q

De novo mutation occurs in ______ cell of parent

A

Germ

23
Q

In hereditary cancer, what is wrong with penetrance?

A

Often incomplete

24
Q

What is retinoblastoma?

A

Most common eye tumour in children.

25
Q

What does identifying children with retinoblastoma early do?

A

Reduce morbidity and mortality.

26
Q

What are the top 3 risk factors of breast cancer?

A

Ageing
Dietary Factors
Family History

27
Q

Do genes work in isolation?

A

No

28
Q

What is the average number of mutations in breast cancer?

A

20,000

29
Q

How many mutations do we have most days?

A

60,000

30
Q

What is the risk of breast cancer of people with BRCA1?

A

50-85%

31
Q

What is the risk of secondary primary breast cancer of people with BRCA1?

A

40-60%

32
Q

What is the risk of ovarian cancer of people with BRCA1?

A

15-45%

33
Q

What is the risk of breast cancer of women with BRCA2?

A

50-85%

34
Q

What is the risk of ovarian cancer of women with BRCA2?

A

10-20%

35
Q

What is the risk of breast cancer in men with BRCA2?

A

6%

36
Q

What are the three highest risk factors of colorectal cancer?

A

Ageing
Personal history of CRC
High fat, low fibre diet

37
Q

What is the carcinoma sequence?

A

Normal epithelium
Hyperproliferative epithelium
Adenoma
Carcinoma

38
Q

Define non-polyposis.

A

Few to no adenomas

39
Q

Define polyposis.

A

Multiple adenomas

40
Q

Where do sporadic HNPCC cancers usually occur?

A

Exit part of colon

41
Q

What type of cells usually have extracolonic cancers?

A

Those which have a high turnover i.e ovary

42
Q

Sebaceous skin tumours are always ______.

A

Benign

43
Q

What is the estimated penetrance for adenomas in FAP?

A

Greater than 90%

44
Q

Untreated polyposis of FAP leads to ___% risk of cancer.

A

100

45
Q

What would 4 or more CHRPE mean?

A

A mutation in the ACP gene.

46
Q

Is attenuated FAP associated with CHRPE?

A

No

47
Q

What are the physical features of attenuated FAP?

A

Upper GI lesions

48
Q

What is recessive MYH polyposis similar to?

A

GI features of attenuated FAP

49
Q

What can multiple modifier genes of lower genetic risk explain?

A

Families with history of cancer and no identified mutation.

Difference in cancer penetrance in families.

50
Q

What 3 ways are there to manage cancer risk?

A

Surveillance
Surgery
Chemoprevention

51
Q

What are 3 problems with gene tests?

A

Not always possible
Mutation may not be related
Variants are unknown significance

52
Q

What are the two types of sequences?

A

Exome

Genome