Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Specialties > Genetics-Predisposition to Cancer > Flashcards

Genetics-Predisposition to Cancer Flashcards

1
Q

What does a normal piece of DNA produce?

A

A normal protein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What would a piece of DNA with an alteration in a single base or with a base removed produce?

A

A non-functioning protein

Or it would shorten the protein via a premature stop codon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What would a piece of DNA with a single base alteration produce?

A

A protein that doesn’t work as well

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is 5-10% of breast cancer due to?

A

A single hereditary gene mutation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is 5-10% of ovarian cancer due to?

A

A hereditary single gene alteration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is 10-30% of colorectal cancer due to?

A

familial basis through polygenic inheritance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is 5% of colorectal cancer due to?

A

A single gene Lynch syndrome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What does a single gene Lynch syndrome cause?

A

Hereditary non-polyposis colorectal cancer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is a tumour caused by?

A

clonal expansion of a cell that contains a mutation within its DNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How does a mutating tumour with a high rate of growth and metastatic potential develop?

A

Within a cell a gene alteration occurs
This genetic alteration is replicated
With each replication, different mutations can occur
this results in a mutating tumour

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What then created a tumour?

A

An accumulation of genetic faults

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Where do somatic mutations occur?

A

non-germline tissues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What type of mutations cause the most cancers?

A

Somatic mutations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Are somatic mutations hereditary?

A

No, they are non-hereditary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How do germline mutations occur?

A

They are inherited from single alteration in egg or sperm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Are germline mutations hereditary or non-hereditary?

A

Hereditary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What do germline mutations cause?

A

Cancer family syndromes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Where are the germline mutations present in the body?

A

In all cells, regardless of the cancer it causes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What do oncogenes control?

A

The first part of the cell growth cycle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What occurs in the S phase (synthesis)?

A

Second part of the cell cycle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What occurs as S phase in the cell cycle?

A

Tumour suppressor genes act

DNA repair genes act

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the percentage chance of germline mutations being passed on?

A

50% chance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Alteration in which phase of the cell cycle predisposes to familial cancer?

A

Alterations in the S phase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

In which type of cancer are oncogenes more common?

A

In Sporadic types of cancer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What do normal cells do?

A

Regulate cell growth

26
Q

What does a normal oncogene do?

A

Regulates cell growth

27
Q

What does a mutation in an oncogene lead to?

A

Accelerated cell division

28
Q

How many mutations in an oncogene is required to cause cancer?

A

One mutation is enough

29
Q

What happens when oncogene ABL fuses with BCR gene?

A

Leads to a fusion protein BCR-ABL

BCR-ABL drives the formation of leukemia

30
Q

What does a mutation in one copy of a gene cause the person to be?

A

A susceptible carries

31
Q

What are the steps in multistep carcinogenesis?

A
  • Normal epithelium
  • Hyper-proliferative epithelium
  • Early adenoma
  • Inter-mediate adenoma
  • Late adenoma
  • Carcinoma
  • Metastasis
32
Q

What is one of the main mechanisms for familial cancer?

A

Familial DNA mismatch repair

33
Q

What is the mechanism of familial DNA mismatch repair?

A

DNA is copied, get an extra base
Failure of mismatch repair gene
Unrepaired DNA is copied, causing a mutation
This is known as an insertion mutation- can be a trigger to cancer

34
Q

How

A
  • Mutations in genes that code for mismatch repair is the mutation in HNPCC
  • A number of genes that code for mismatch repair can be mutated
  • Tumour is usually in proximal colon
35
Q

How is there a good chance for prevention in colorectal cancer?

A

Adenoma-carcinoma sequence for polyp formation

36
Q

What are the 2 main clincial features of colorectal cancer?

A

Age of onset variable but normally around 45

Tumour occurs in proximal colon

37
Q

Which cancers does Lynch syndrome increase the chance of?

A
  • Endometrial cancer
  • Urinary tract cancer
  • Ovarian cancer
  • Gastric cancer
38
Q

What are BRCA1 and BRCA2 associated with?

A

Familial breast and ovarian cancer

39
Q

Which cancers are BRCA1 and BRCA2 associated with?

A

Breast and Ovarian cancer

40
Q

How does having the BRCA1 gene increase risk of developing breast cancer?

A

Increases chance by 60-80%

About 50% get second primary breast cancer

41
Q

What percentage of women get Ovarian cancer with the BRCA1 gene?

A

50% get ovarian cancer

42
Q

What percentage of women get Ovarian cancer with the BRCA2 gene?

A

20% get ovarian cancer

43
Q

What does BRCA2 increase the chance of developing in men?

A

Increased risk of breast and prostate cancer

44
Q

What type of inheritance does familial cancer have?

A

Autosomal dominant inheritance

45
Q

What does autosomal dominant inheritance mean?

A
  • Each child has a 50% chance of inheriting the mutation
  • No skipped generation
  • Equally transmitted by men and women
46
Q

What is Mendelian Risk?

A

In a dominant high penetrance syndrome
• Offspring of an affected individual has a 50% chance of carrying the mutation and getting the condition
• Their offspring will only have a 25% chance of carrying the mutation

47
Q

When should you suspect hereditary cancer?

A
  • Cancer in 2 or more close relatives (on same side of family)
  • Early age at diagnosis
  • Multiple primary tumors in the same person
  • Bilateral or multiple rare cancers
  • Characteristic pattern of tumours (e.g. breast and ovary)
  • Evidence of autosomal dominant transmission
48
Q

What happens in a Clinical Genetics Consultation?

A
  • Go through family history
  • Risk estimation
  • Explanation of basis of risk
  • Genetic testing- if high risk
49
Q

What interventions might you suggest to someone at risk of cancer?

A
  • Increased awareness of signs and symptoms
  • Lifestyle: Diet, smoking, exercise
  • Prevention: Oestrogen, aspirin
  • Screening
  • Prophylactic surgery
50
Q

When would you first do a mammography for breast cancer?

A

5 years younger than the first cancer in the family

51
Q

If there was a high risk of someone developing breast cancer what would you suggest?

A

Annual breast examination by the doctor

52
Q

What would you offer to patients who were at moderate risk of breast cancer?

A

Mammography 2 yrly from 35-40, yrly from 40-50

53
Q

What would you offer to patients who were at moderate risk of breast cancer?

A

Mammography 2 yrly from 35-40,

yearly from 40-64

54
Q

What genetic testing might you consider in high risk patients for breast and ovarian cancer?

A

BRCA1 and BRCA2 genetic testing

55
Q

What would significantly reduce the chance of a carrier developing breast cancer?

A

Mastectomy- removal of breast tissue

Reduces chance of breast cancer to 5%

56
Q

What is done to eliminate the risk of primary ovarian cancer?

A

Prophylactic oophorectomy

57
Q

What does Prophylactic oophorectomy do?

A

Induces surgical menopause so women given HRT till 50

58
Q

How often is a colonoscopy carried out in a gene carrier for CRC?

A

2 yearly from 25

59
Q

How often is a colonoscopy carried out in someone who is at moderate to high risk of CRC?

A

5 yearly from 50 to 70

60
Q

How often is a colonoscopy carried out in someone who is at low to moderate risk of CRC?

A

Once at 55

61
Q

What is someone who is a gene carrier for CRC told to take prophylactically?

A

Prophylactic aspirin

62
Q

How can it be determined if a cancer is lynch syndrome associated?

A

Test for mismatch repair gene proteins via immunohistochemistry (IHC) or microsatellite instability testing (MSI)

Specialties (18 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions