Brainscape's Knowledge GenomeTM

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


See full index

Isaak: Genetics MBS > Exam II Review Slides > Flashcards

Exam II Review Slides Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

List the four current screening (non-invasive) techniques.

A
  1. Maternal serum screening
  2. Sequencing of cell-free DNA in maternal plasma (NIPT)
  3. Prenatal ultrasound
  4. Fetal MRI
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

List the five current diagnostic (invasive) techniques.

A
  1. Amniocentesis
  2. Chorionic villus sampling
  3. Cordocentesis
  4. Fetal biopsy
  5. Pre-implantation genetic diagnosis (PGD)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

List the timeline for prenatal testing.

A

Pre-

PGD

8-10 Weeks

Dating US

9-10+ Weeks

NIPT

11-13 Weeks

NT, MSS, CVS

15-18 Weeks

2nd Trimester MSS

15-19 Weeks

Amnio

18-20 Weeks

Fetal Anomaly Scan

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

What are the three widely accepted clinical applications for PGD?

A
  1. Single gene diagnosis by PCR
  2. Familial chromosome arrangement by FISH
  3. Fetal sex selection
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

When is it acceptable to perform PGD when there is a single gene diagnosis by PCR?

A
  1. Autosomal
  2. X-Linked (usually untreatable or lethal)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

When is it acceptable to perform PGD when there is a familial chromosome rearrangement detected by FISH?

A
  1. Reciprocal or Robertsonian Translocation
  2. Pericentric Inversion***

***Not taught

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

When is it acceptable to perform PGD for sex selection?

A
  1. X-linked conditions
  2. Autism
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are four controversial indications for PGD?

A
  1. Pre-disposition for adult-onset disorders.
  2. Aneuploidy screening by FISH
  3. Sex selection for “family balance”
  4. Creation of HLA-matched stem cell donros
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What conditions are controversial for PGD in regards to pre-disposition for adult-onset disorders?

A
  1. Breast cancer
  2. Autosomal dominant cancer syndromes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What conditions are controversial for PGD in regards to aneuploidy screening by FISH?

A
  1. AMA
  2. Recurrent SAB
  3. Creation of HLA-matched stem cell donors.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

At what block in Meiosis does heterodisomy occur?

A

A non-disjunction in Meiosis I.

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

At what block in Meiosis does isodisomy occur?

A

A non-disjunction in Meiosis II.

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

When does trisomic rescue occur?

A

It occurs when there is a detected trisomy. It wants to get rid of the extra chromosome, but doesn’t always get the right one.

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

How does UPD occur?

A

A poorly executed trisomic rescue. A trisomic rescue can indeed create normal cells with the correct chromosome, but can sometimes “kill” the new (or outsider) chromosome, resulting in UPD. UPD is a result of a trisomic rescue that TRIES to fix heterodisomy or isodisomy.

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

What is a translocation?

A

The exchange of material between two or more chromosomes.

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

What are the two types of translocations that can occur?

A
  1. Balanced (reciprocal)
  2. Unbalanced
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Ubalanced translocations will have a combination of ____ and ____.

A

Monosomy and trisomy.

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

Close your eyes.

What is an example karyotype for a Robertsonian Translocation?

A

45,XY,der(15;22)(q10;q10)

45,XX,der(13;14)(q10;q10)

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

What does the following karyotype mean?

45,XX,der(14;21)(q10;q10),+21

A

Robertsonian Translocation–down syndrome!

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

What’s more serious, a deletion or an unbalanced translocation?

A

Definitely a deletion.

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

What can a deletion be used for?

A

Identifying genes involved in a phenotype.

FAP (APC) was mapped due to a child with ID and polyps.

Retinoblastoma was also mapped due to inherited forms of cancer.

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

How can one derive the shortest region of overlap, and why is the SRO significant?

A

You can compare multiple individuals with the same disorder and chromosome change, deriving the SRO, therefore “narrowing down” where the gene of interest/significance that was deleted–is located.

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

SRO

A

The region that is deleted in all samples, which is generally defined as the smallest deletion among many samples.

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

How does the ISCN assignment of break points work?

A

The smallest numbers are closest to the centromere, and the largest numbers are at the end of the chromosome.

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

p

A

The “petite” or short side of the chromosome, oriented upwards in a karyotype.

26
Q

q

A

The “long” side of a chromosome, usually oriented downwards.

27
Q

What does the following karyotype indicate? 46XY,del(11)(q13)

A

All the material from band q13 to end of the chromosome is deleted.

28
Q

What does the following karyotype indicate?

46,XY,del(q13q23)

A

Only the material between q13 and q23 has been deleted.

29
Q

What is the SRO? 46XY,del(11)(q13) 46,XY,del(q13q23)

A

q13 to q23

30
Q

On what chromosome does the deletion occur that results in Prader-Willi and Angelman syndrome?

A

Chromosome 15

31
Q

What percent of cancers are due to sporadic mutations?

A

90%

32
Q

What percent of cancers are due to inherited predisposition?

A

10%

33
Q

How many mutations does a cancer cascade require?

A

Two mutations.

34
Q

Predisposition to cancer is inherited–in an autosomal dominant fashion. What does this imply?

A

There is incomplete penetrance (“if”) and variable expressivity (“when” or “where”).

35
Q

At the cellular level, what is required for cancer to develop?

A

Two mutations.

36
Q

All cancers are due to ____, but most are not inherited, they are are acquired.

A

mutations

37
Q

Mutations that cause cancer can result in two phenotypes on the cellular level. What are they?

A
  1. Loss of function.
  2. Gain of function.
38
Q

Loss of function tumorigenesis is more common with…

A

…inherited predisposition syndromes.

39
Q

In regards to loss of function tumorigenesis, how many copies must be lost to cause cancer?

A

Both copies.

40
Q

What are the four tumor suppressor genes associated with loss of function tumorigenesis? What do they do?

A
  1. Rb 2. NF1 3. p53 4. APC They are tumor suppressors; they restrain cell growth.
41
Q

What are the three mismatch repair genes associated with loss of function tumorigenesis? What do they do?

A
  1. MLH1
  2. MSH2
  3. MSH6

Maintain correct DNA sequences.

42
Q

In regards to gain of function tumorigenesis, how many copies must be lost to cause cancer?

A

A single somatic gene mutation can cause cancer.

43
Q

In what kind of genes does find gain of function mutations?

A

Growth and transcription factors.

44
Q

What kind of oncogenes are associated with gain of function?

A

RET and BCR-ABL

45
Q

What are the seven red flags for hereditary cancer?

A
  1. Early onset of cancer (<50)
  2. Multiple or bilateral tumors
  3. Rare or unusual tumors
  4. Combinations of ceratin cancers
  5. Autosomal dominant pattern of inheritance
  6. Testing identifies same mutation in affectedindividuals and not in unaffected individuals
  7. Lack of known contributing factors
46
Q

Autosomal Dominant (Affected Parent)

A
47
Q

Autosomal Dominant (both parents affected)

A
48
Q

X-Linked Dominant (affected father)

A
49
Q

X-Linked Dominant (affected mother)

A
50
Q

Autosomal Recessive (carrier parents)

A
51
Q

X-Linked Recessive (affected father)

A
52
Q

X-Linked Recessive (carrier mother)

A
53
Q

Multiplication Rule

A
54
Q

Addition Rule

A
55
Q

Hardy Weinberg

A
56
Q

Tricky Questions

A
57
Q

Risk and Testing (Example)

A
58
Q

Chance of one affected offspring in AR family (example)

A
59
Q

Example Q

A
60
Q
A

Isaak: Genetics MBS (10 decks)

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