Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

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
What do normal cells do?
Regulate cell growth
26
What does a normal oncogene do?
Regulates cell growth
27
What does a mutation in an oncogene lead to?
Accelerated cell division
28
How many mutations in an oncogene is required to cause cancer?
One mutation is enough
29
What happens when oncogene ABL fuses with BCR gene?
Leads to a fusion protein BCR-ABL | BCR-ABL drives the formation of leukemia
30
What does a mutation in one copy of a gene cause the person to be?
A susceptible carries
31
What are the steps in multistep carcinogenesis?
* Normal epithelium * Hyper-proliferative epithelium * Early adenoma * Inter-mediate adenoma * Late adenoma * Carcinoma * Metastasis
32
What is one of the main mechanisms for familial cancer?
Familial DNA mismatch repair
33
What is the mechanism of familial DNA mismatch repair?
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
How
* 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
How is there a good chance for prevention in colorectal cancer?
Adenoma-carcinoma sequence for polyp formation
36
What are the 2 main clincial features of colorectal cancer?
Age of onset variable but normally around 45 | Tumour occurs in proximal colon
37
Which cancers does Lynch syndrome increase the chance of?
* Endometrial cancer * Urinary tract cancer * Ovarian cancer * Gastric cancer
38
What are BRCA1 and BRCA2 associated with?
Familial breast and ovarian cancer
39
Which cancers are BRCA1 and BRCA2 associated with?
Breast and Ovarian cancer
40
How does having the BRCA1 gene increase risk of developing breast cancer?
Increases chance by 60-80% | About 50% get second primary breast cancer
41
What percentage of women get Ovarian cancer with the BRCA1 gene?
50% get ovarian cancer
42
What percentage of women get Ovarian cancer with the BRCA2 gene?
20% get ovarian cancer
43
What does BRCA2 increase the chance of developing in men?
Increased risk of breast and prostate cancer
44
What type of inheritance does familial cancer have?
Autosomal dominant inheritance
45
What does autosomal dominant inheritance mean?
* Each child has a 50% chance of inheriting the mutation * No skipped generation * Equally transmitted by men and women
46
What is Mendelian Risk?
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
When should you suspect hereditary cancer?
* 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
What happens in a Clinical Genetics Consultation?
* Go through family history * Risk estimation * Explanation of basis of risk * Genetic testing- if high risk
49
What interventions might you suggest to someone at risk of cancer?
* Increased awareness of signs and symptoms * Lifestyle: Diet, smoking, exercise * Prevention: Oestrogen, aspirin * Screening * Prophylactic surgery
50
When would you first do a mammography for breast cancer?
5 years younger than the first cancer in the family
51
If there was a high risk of someone developing breast cancer what would you suggest?
Annual breast examination by the doctor
52
What would you offer to patients who were at moderate risk of breast cancer?
Mammography 2 yrly from 35-40, yrly from 40-50
53
What would you offer to patients who were at moderate risk of breast cancer?
Mammography 2 yrly from 35-40, | yearly from 40-64
54
What genetic testing might you consider in high risk patients for breast and ovarian cancer?
BRCA1 and BRCA2 genetic testing
55
What would significantly reduce the chance of a carrier developing breast cancer?
Mastectomy- removal of breast tissue | Reduces chance of breast cancer to 5%
56
What is done to eliminate the risk of primary ovarian cancer?
Prophylactic oophorectomy
57
What does Prophylactic oophorectomy do?
Induces surgical menopause so women given HRT till 50
58
How often is a colonoscopy carried out in a gene carrier for CRC?
2 yearly from 25
59
How often is a colonoscopy carried out in someone who is at moderate to high risk of CRC?
5 yearly from 50 to 70
60
How often is a colonoscopy carried out in someone who is at low to moderate risk of CRC?
Once at 55
61
What is someone who is a gene carrier for CRC told to take prophylactically?
Prophylactic aspirin
62
How can it be determined if a cancer is lynch syndrome associated?
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.
© 2025 Bold Learning Solutions. Terms and Conditions