Molecular medicine I Flashcards

1
Q

What are the two steps in gene analysis?

A

Finding a correlation between a mutation and a disease

Detecting or predicting a disease based on knowledge obtained in the first phase

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2
Q

What is the direct method of mutation detection? What are its limitations?

A

Correlating a disease with a particular fragment of DNA

Limit = really time intensive (decades)

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3
Q

What is the indirect method of mutation detection? What are its limitations?

A

Following the inheritance of a marker. Marker may crossover (5% chance of this, thus test only 95% accurate)

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4
Q

What is the sanger method of DNA sequencing?

A

recopying DNA stands 4 times, adding labeled ACTor G adenine, then putting together like a jigsaw

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5
Q

What percent of the human genome actually has open reading frames?

A

3%

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6
Q

What percent of the genome varies between each person?

A

<1%

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7
Q

What are the two limits for sequencing?

A

Does not show on which chromosome mutation is

Will not show deletions or duplications of a chromosomal region

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8
Q

What does the term copy number variant refer to?

A

The fact that normal humans beings have small chromosomal insertions and deletions which (usually) do not have a major effect. (there are non diploid states of chromosomes)

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9
Q

What is comparative genome hybridization used for?

A

To determine the presence of CNVs

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10
Q

When is fluorescence in situ hybridization used?

A

To identify a chromosomal locus on a metaphase chromosome

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11
Q

What is hybridization?

A

Annealing of DNA strands together–utilized when you want to see if a patient has a DNA stand segment or not.

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12
Q

What is the polymerase chain reaction?

A

Using Polymerase to amplify the number of DNA strands based on the template strand of a patient.

(carried out by adding specific primers to block off region of interest, then changing temp)

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13
Q

How does PCR detect mutations?

A
  1. By adding primers that will only bind to mutants

2. seeing if primers deleted (large length change in DNA)

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14
Q

What is PCR used?

A

Qualitative testing of mutations

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15
Q

What technique would you use to get quantitative data on gene mutations?

A

Real-time PCR

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16
Q

What are the two independent factors in real time PCR?

A

Amount of template

number of PCR cycles

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17
Q

What is the dependent factors in real time PCR?

A

Amount of amplified DNA

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18
Q

What is reverse-transcriptase PCR used for?

A

Detection of RNA amounts (HIV load, expression of CA genes)

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19
Q

What does the enzyme reverse transcriptase do in reverse transcriptase PCR?

A

Synthesizes a DNA strand from RNA (rest of procedure follows PCR technique)

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20
Q

Why is it important that small oligonucleotides have very high sequence complementarity in Allele-specific oligonucleotide mutation detection?

A

means that they are extremely selective in what they bind to (will only bind to mutant/normal gene, and thus will cause only one spot on the plate to become positive)

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21
Q

What are DNA microarrays?

A

Plates that contain all known DNA defects that lead to disease. Can use the ASO concept to screen patients for genetic diseases.

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22
Q

How can CA cells be analyzed by ASOs?

A

Change the mRNA to cDNA by reverse transcriptase, using labeled nucleotides. Release onto ship with known DNA mutations.

23
Q

What is malignant hyperthermia?

A

Mutation in Ryanodine receptor that causes the efflux of Ca in muscle cells, if there is halothane and succinyl-choline

24
Q

What does warfarin inhibit?

A

Vitamin K epoxide reductase

25
Q

What are the two sources of possible mutations that can change the way warfarin is degraded?

A

Polymorphism in CYP2C9 (codes for p450) –> lower tolerance

Mutation in subunit of vitamin K expoxide reductase (VKORC1) –> increased tolerance

26
Q

What are the two ways to collect a sample from a fetus for genetic testing?

A

Amniocentesis (15/16 weeks withdrawn amniotic fluid)

Chorionic villus sampling (cells from chorion taken at 10-12 weeks)

27
Q

Why is chorionic villus sampling riskier than amniocentesis? What is the advantage?

A

Risky b/c chance of missing mosacism

Able to do it earlier

28
Q

How are epigenetic changes analyzed?

A

minute amount of DNA treat methylated DNA with chemicals

29
Q

How are proteins detected and quantified?

A

With antibodies

30
Q

The antibodies used in protein detection can do what three things?

A

Detect presence of antigen
Quantify antigen
localize antigens in vivo

31
Q

What type of cells produce antibodies?

A

B cells

32
Q

What is the area of the antigen that antibodies bind to?

A

Epitope

33
Q

How many types of antibodies can B cells produce?

A

1

34
Q

What are monoclonal antibodies? What are polyclonal antibodies?

A

Polyclonal = “Antibodies that are secreted by different B cell lineages within the body (whereas monoclonal antibodies come from a single cell lineage)”: -Wikipedia

35
Q

What is the sandwich model of ELISA?

A

Antibodies for protein on bottom
Antigen/protein in the middle
Receptor molecule on top

36
Q

What is the sandwich model of ELISA used for?

A

Quantification of proteins

PTH, HbA1c, CRP

37
Q

What is the indirect model of ELISA?

A

Anitgen linked to bottom.
Serum added
General antibodies with receptor added.

38
Q

What is the indirect model of ELISA used for?

A

HIV and autoimmune diseases

39
Q

What protein detection technique would you use to test for RA? What is the antigen in this case?

A

Indirect ELISA–immunoglobin G

40
Q

What is western blotting used for?

A

Indicated molecular weight

41
Q

What are the two specific used for Western blotting in the handout?

A
Confirm HIV (Need two tests)
Diagnose parasite infections
42
Q

What is the sample used, and what is it detecting: Direct sequencing

A

DNA

Point mutations/SNPs

43
Q

What is the sample used, and what is it detecting: Whole exome sequencing

A

DNA

Point mutations/SNPs in the entire genome

44
Q

What is the sample used, and what is it detecting: SNP typing

A

DNA

SNPs in the entire genome

45
Q

What is the sample used, and what is it detecting: Polymerase chain reaction

A

DNA

Small insertions and deletions

46
Q

What is the sample used, and what is it detecting: Reverse transcriptase PCR

A

RNA

Expression levels for a small number of genes

47
Q

What is the sample used, and what is it detecting: Allele specific oligonucleotides

A

DNA

Point mutations, small insertions/deletion

48
Q

What is the sample used, and what is it detecting: Gene expression array

A

RNA

Expression levels of thousands of genes-not intergenic region or introns

49
Q

What is the sample used, and what is it detecting: methylated DNA PCR

A

DNA

Epigenetic changes, DNA methylation

50
Q

What is the sample used, and what is it detecting: comparative genome hybridization

A

DNA

insertions, deletions, and aneuploidies in the kilo to megabase range

51
Q

What is the sample used, and what is it detecting: FISH

A

DNA

Copy number of a selected chromosome

52
Q

What is the sample used, and what is it detecting: ELISA

A

Proteins

Amounts of protein in a sample

53
Q

What is the sample used, and what is it detecting: Western blot?

A

Proteins

Amounts and size of proteins in sample