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Flashcards in Molecular Path Deck (49):
1

What are the four applications of molecular techniques?

1. Detection of inherited/acquired mutations
2. Accurate diagnosis/classify tumor
3. Detect infx agents
4. Tissue typing, paternity testing

2

What are the advantages to molecular analysis over cytogenetic analysis?

Sensitive (genes are stable relative to proteins)

Not dependent on analysis of gene product

3

What are genome mutations?

The loss or gain of an entire chromosome

4

What are chromosome mutations?

Rearrangement of genetic material

5

What are gene mutations?

the complete deletion of a gene, or as little as a single point mutation

6

Where can gene mutations occur?

Introns, extrons

7

Triplet CAG repeat in an extron = ?

Huntingtons disease

8

CTG repeat in an UTR = ?

Myotonic dystrophy

9

What are the effects of mutations in promoters/enhancer regions of a DNA segment?

Increase or decrease in expression

10

Which are expressed, and which are cut out: exons and introns?

Exons = expressed
Introns = cut out

11

What is the molecular basis of beta-thalassemia?

problem with the polyadenylation signal or in the promoter regions, causing a decreased expression

12

What is the direct detection of mutations?

DNA comparison with a known DNA sequence

13

What is an indirect detection?

Detection through linkage of the disease gene with a marker that is nearby

14

What are the three steps of direct detections of mutations?

1. PCR amplification via primer
2. Digest PCR products with appropriate endonuclease
3. Separate digestion product with electrophoresis

15

What is allele-specific extension strategy?

For a **known** mutation, a primer is made before the mutated point. Then, marked nucleotides are added. Since point mutation is known, then the markers will indicate whether it is a wild, mutated, or mixed gene.

16

What is allele-specific extension strategy?

For a known mutation, a primer is made up until the mutated point. Then, marked nucleotides are added. Since point mutation is known, then the markers will indicate whether it is a wild, mutated, or mixed gene.

17

How are linkage analysis analyzed?

Endonuclease used to cut marker gene

Southern blot will display different cut genes of the specific gene in question (d/t the use of a probe)

18

What is the difference between linkage analysis and detection of genetic mutations through endonucleases?

A specific probe is used to only look at the mutated linker gene in question, rather than run all of the DNA in an electrophoresis

19

What is the use of genetic techniques for HIV and Hep C?

Monitor Viral load via [RNA]

20

What is the difference between linkage analysis and detection of genetic mutations through endonucleases?

A specific probe is used to only look at the mutated linker gene in question, rather than run all of the DNA in an eletrophoresis

21

What is indirect detection of a gene?

Through linkage of the disease gene with a marker that is nearby

22

What are the advantages of indirect detection/linkage analysis?

Does not require gene sequence to be known

Does require that polymorphism is sufficiently close to the mutation

23

How are linkage analysis analyzed?

Endonuclease used to cut marker gene

Southern blot will display different cut genes

24

What is spectral karyotyping (SKY)? What is this technique used for?

Painting all chromosomes a specific color, looking for translocations

25

What is the use of genetic techniques for HIV?

Monitor Viral load

26

What is PCR used for?

Detect type of infectious agent.

27

What are the characteristics of a gene that can be used to identify an individual?

Must by highly polymorphic (like MHC)

28

What is the purpose of a ladder in DNA analysis?

the ladder is a control DNA segment for DNA size

29

Can you totally exclude/include suspects with DNA forensic analysis? Why or why not?

Can totally exclude
Cannot totally include b/c MHC not completely unique

30

FISH =?

Staining DNA and looking for abnormal numbers

31

What is spectral karyotyping?

Painting all chromosomes a specific color, looking for translocations

32

What is the array-based comparative genomic hybridization?

Color labeled normal and abnormal genes hybridized to sample. ***

33

What is aneuploidy?

Lack of a chromosome (like Down)

34

What causes Beta-thalassemia?

Point mutation in the promoter/enhancer changes gene expression

Changes in the 5' cap

35

Is PCR direct or indirect technique of detecting genetic mutations?

Direct

36

What are the two major advantages of molecular analysis over karyotyping?

1. Sensitivity
2. Not gene product dependent--any cell works

37

CF is caused by what genetic mutation?

Frameshift mutation

38

What is RFLP (restriction fragment length polymorphism)?

Mutation causes addition or subtraction of an endonuclease site. Therefore, different gene fragment lengths are produced

39

What is the principle behind RFLP (restriction fragment length polymorphism)?

Mutation causes addition or subtraction of an endonuclease site. Therefore, different gene fragment lengths are produced

40

What is the method of detection of RFLP?

Southern blot of amplified sample gene, compared to a normal gene (must know normal)

41

What is the difference between direct and indirect detection of RFLP?

Direct = it is the loss of the endonuclease site that causes the disease

Indirect = only correlated

42

What are the advantages of indirect detection RFLP?

Advantage = do not need to know specific gene, just closely associated one

43

CGG repeat on an X chromosome= ?

Fragile X sydrome

44

GAA repeat in an intron = ?

Friedreich ataxia

45

A mutation in the 3' polyadenylation signal may lead to what?

Unstable mRNA = not expressed protein, or decreased expression

46

How does forensic medicine work?

Run MHC genes of suspected persons with evidence, and compare

47

Where do epigenetic changes usually occur?

at promoters at the CpG islands

48

Histone deacetylation is associated with an increase or a decrease in gene expression?

Decrease

49

What is array-based comparative genomic hybridization?

Tested DNA and reference DNA are labeled with two fluorescent dyes and hybridized to slide spotted with DNA probes. This can detect amplification or deletion of a gene, depending on the color at each probe.