Molecular diagnostic-Molecular Diagnostics Flashcards
1
Q
- Which method is most useful for confirmation
that a culture isolate is Group B streptococcus?
A. Southern blotting
B. Polymerase chain reaction
C. Direct hybridization
D. Probe capture assay
A
C. Direct hybridization
2
Q
- In situ hybridization (ISH) tests for human
papilloma virus (HPV) using cervical smears
differ from immunochemical staining of tissue in
which regard?
A. ISH has lower analytical sensitivity
B. ISH has lower analytical specificity
C. ISH differentiates subtypes more easily
D. ISH differentiates cervical neoplasia from
genital warts
A
C. ISH differentiates subtypes more easily
3
Q
- Which method is most sensitive for detection of
viral meningitis?
A. Viral culture
B. CSF WBC count
C. Specific antibody testing of CSF for viral
antigens
D. Real-time RT-PCR
A
D. Real-time RT-PCR
4
Q
- What gene must be amplified in PCR to
differentiate methicillin-resistant Staphylococcus
aureus from methicillin-resistant coagulase-negative
Staphylococcus?
A. orfX
B. mecA
C. VanA
D. iles-2
A
A. orfX
5
Q
- Which statement best describes real-time PCR
testing for Mycobacterium tuberculosis?
A. The test is positive only in cases of smear-positive
and culture-positive infections
B. The test has a sensitivity of > 99% on all
specimen types when compared to culture
C. The test can detect 85%–90% of smear-negative,
culture-positive infections
D. The test sensitivity is near 100% but specificity is
approximately 80%
A
C. The test can detect 85%–90% of smear-negative,
6
Q
- How can cell proliferation be explained by the
BCR/ABL gene rearrangement that occurs in
the 9:22 translocation that causes the Ph1
chromosome of CML?
A. It causes underexpression of p53
B. A hybrid protein is made that up-regulates the
cell cycle
C. Translocation induces a point mutation in the
ABL oncogene
D. ABL activates p23
A
B. A hybrid protein is made that up-regulates the
cell cycle
7
Q
- Which statement accurately describes the clinical
utility of translocation testing in leukemia?
A. Relapse is predicted by any new translocation
occurring after treatment
B. Specific translocations associated with a type
of leukemia will occur in all cases
C. Translocation products for each leukemia
subtype are always the same
D. Translocation is a sensitive way to identify
surviving leukemic cells following treatment
A
D. Translocation is a sensitive way to identify
surviving leukemic cells following treatment
8
Q
- Which is the most sensitive method of minimal
residual disease testing in chronic myelogenous
leukemia?
A. Karyotyping analysis
B. FISH
C. Flow cytometry
D. RT-PCR
A
D. RT-PCR
9
Q
- How can cell proliferation be explained by the
BCL 2 translocation t(14;18) that occurs in
up to 90% of persons with follicular B-cell
lymphoma?
A. p53 is underexpressed
B. A hybrid protein is made that up-regulates the
cell cycle
C. Transcription of the BCL 2 oncogene is
increased by the translocation
D. The BCL 2 gene joins with the p21 gene,
making it inactive
A
C. Transcription of the BCL 2 oncogene is
increased by the translocation
10
Q
- Which mechanism is responsible for
retinoblastoma?
A. Mutation of a tumor suppressor gene
B. Mutation of a tyrosine kinase gene
C. Activation of an oncogene
D. Deletion of a gene encoding a GTPase
activator
A
A. Mutation of a tumor suppressor gene
11
Q
- Which oncogene is involved in the etiology of
Burkitt’s lymphoma?
A. ABL
B. Myc
C. Ras
D. HER/neu
A
B. Myc
12
Q
- The majority of cases of Duchenne’s muscular
dystrophy are caused by which type of genetic
damage?
A. Point mutation
B. Insertion
C. Deletion
D. Trinucleotide repeats
A
C. Deletion
13
Q
- How are cases of Duchenne’s muscular dystrophy
not detected by PCR usually confirmed?
A. DNA sequencing
B. Linkage analysis
C. Macroarray analysis
D. Dystrophin protein staining
A
B. Linkage analysis
14
Q
- Inheritance of BRCA1 or BRCA2 mutations
increases the risk of breast and ovarian cancer
by which mechanism?
A. Oncogene production
B. Transcription signaling by the mutant protein
C. Deficient tumor suppressor function
D. Chimeric protein production
A
C. Deficient tumor suppressor function
15
Q
- Polymorphisms of the cytochrome p450 genes
are important in identifying which condition?
A. Poor drug metabolism
B. Risk for primary biliary cirrhosis
C. Progression of hepatitis C to hepatic cirrhosis
D. Parentage in cases where HLA results are
inconclusive
A
A. Poor drug metabolism
16
Q
- Approximately how may mutations have been
identified in the gene coding for the cystic fibrosis
trans membrane conductor regulator protein
(CFTR)?
A. 10
B. 100
C. 1,000
D. 10,000
A
C. 1,000
17
Q
- Which statement about CF is accurate?
A. A sweat chloride test is abnormal in all forms
of CF
B. Immunoreactive trypsin is deficient in all persons
with CF
C. Some CF mutations can cause male infertility
with no other symptoms
D. The CF genotype always predicts the severity of
the disease
A
C. Some CF mutations can cause male infertility
18
Q
- Which of the following alleles has the highest
frequency in the general population?
A. ΔF508 (cystic fibrosis)
B. Factor V-Leiden (hereditary thrombophilia)
C. Prothrombin G20210A (hereditary
thrombophilia)
D. Methylene tetrahydrofolate reductase mutation
C677T homocysteinemia
A
D. Methylene tetrahydrofolate reductase mutation
C677T homocysteinemia
19
Q
- HLA typing can be done by which molecular
method?
A. PCR analysis using 96 well microtrays with allele
or groups specific primers in each
B. Restriction fragment length polymorphism
testing
C. Direct hybridization with WBCs on a peripheral
blood film
D. Fluorescent in situ hybridization reactions with
peripheral blood lymphocytes
A
A. PCR analysis using 96 well microtrays with allele
or groups specific primers in each
20
Q
- Which statement best describes the relationship
between HLA DNA typing and serological
haplotypes?
A. One or two bands are seen for each locus
correlating to reactivity with a specific antigen or
group of antigens
B. HLA alleles cannot be related to HLA antigens
because antisera specificity is unrelated to genetic
polymorphism
C. A single antibody specificity always corresponds
to a single allele
D. Not all HLA genes produce antigens recognized
by antibodies
A
A. One or two bands are seen for each locus
correlating to reactivity with a specific antigen or
group of antigens
21
Q
- Highest-resolution HLA typing is needed for
which of the following transplants?
A. Heart
B. Liver
C. Kidney
D. Bone marrow
A
D. Bone marrow
22
Q
- Which method of DNA analysis is used most often
to detect the hemoglobin S gene?
A. FISH
B. PCR followed by RFLP
C. Cytogenetic analysis of chromosome 11
D. Labeled probe painting of chromosome 11
A
B. PCR followed by RFLP
23
Q
- Which of the following genetic diseases is caused
by an expanded trinucleotide repeat?
A. Prader–Willi syndrome
B. Angelman’s syndrome
C. Fragile X syndrome
D. Williams’ syndrome
A
C. Fragile X syndrome
24
Q
- Which is the most common method used for
parentage testing in the United States?
A. Short tandem repeat analysis
B. Nuclear DNA sequencing
C. HLA DNA typing
D. Mitochondrial DNA sequencing
A
A. Short tandem repeat analysis
25
Q
- In order to prove exclusion in DNA paternity
testing, why must two genes be identified that
must come from the biological father and
did not?
A. A single exclusion can result from laboratory
error
B. A single exclusion can result from germ line
mutation within one locus being tested
C. The biological father may be a blood relative to
the alleged father
D. The biological mother may be different than the
purported mother
A
B. A single exclusion can result from germ line
mutation within one locus being tested
26
Q
- Hereditary hemochromatosis is the result of which
type of mutation?
A. Nonsense mutation
B. Microdeletion
C. Translocation
D. Single nucleotide substitution
A
D. Single nucleotide substitution
27
Q
- p21 is a GTP binding protein produced by which
oncogene?
A. RET
B. Ras
C. HER-2/neu
D. N-Myc
A
B. Ras
28
Q
- Which of the following thalassemias can be
detected by PCR followed by blotting with
a single specific oligonucleotide probe?
A. α-Thalassemia
B. Hemoglobin S/β-thalassemia
C. β-Thalassemia
D. Hemoglobin S/β-thalassemia
A
A. α-Thalassemia
29
Q
- Which method is used to determine if the
hemoglobin C gene is present in fetal cells?
A. Chromosome painting
B. FISH
C. Restriction enzyme analysis
D. PCR followed by blotting with a specific
oligonucleotide probe
A
D. PCR followed by blotting with a specific
oligonucleotide probe
30
Q
- In flow cytometry, the term “gating” refers to:
A. Selection of a subpopulation of cells to count
B. Determining the fluorescent emission spectrum
of cells of interest
C. Interference caused by binding of more than a
single antibody
D. Selecting the appropriate counting aperture
A
A. Selection of a subpopulation of cells to count
31
Q
- Which of the following parameters are used to gate
cells processed by the flow cytometer?
A. Font surface fluorescence versus incident laser
intensity
B. Forward light scatter versus side scatter
C. The ratio of light emitted at two different
wavelengths
D. Impedance amplitude versus background
conductance
A
B. Forward light scatter versus side scatter
32
Q
- In general, which statement best characterizes the
relationship between white blood cells and light
scattering in flow cytometry?
A. Forward scatter is related to cell size and side
scatter to granularity
B. Forward scatter is related to nuclear density and
side scatter to size
C. Forward scatter is inversely related to size and
side scatter is directly related to size
D. Forward scatter
A
A. Forward scatter is related to cell size and side
scatter to granularity
33
Q
- Fluorescent dyes most commonly conjugated to
antibodies used in flow cytometry are:
A. Fluorescein isothiocyanate and Texas red
B. Calcofluor white and Texas red
C. Phycoerythrin and fluorescein isothiocyanate
D. Acridine orange and rhodamine
A
C. Phycoerythrin and fluorescein isothiocyanate
34
Q
- A cell population is positive for surface markers
CD45, CD3, CD4, and Tdt. Which type of
leukocytes are these?
A. Lymphocytes
B. Granulocytes
C. Monocytes
D. Early myeloid precursors
A
A. Lymphocytes
35
Q
- A FISH test is performed on a slide of peripheral
blood leukocytes. The test uses a dual fusion
probe, consisting of a Spectrum Green labeled
probe to the BCR 22 q11.2 locus, and a Spectrum
Orange labeled probe to ABL 9q34. What disease
is this test for?
A. Chronic myelogenous leukemia
B. Multiple myeloma
C. Bladder cancer
D. Thyroid cancer
A
A. Chronic myelogenous leukemia
36
Q
- A tissue sample for DNA analysis by PCR
was processed for DNA by simple lysis and
proteinase K digestion. The lysate was diluted
1:100 and its absorbance measured in an
ultraviolet spectrophotometer at 260 nm and
280 nm. The absorbance ratio 260:280 was
1.2. What does this indicate?
A. The DNA concentration is too high for PCR
B. The DNA concentration is too low for PCR
C. The sample contains too much protein
D. The sample is optimal for PCR
A
C. The sample contains too much protein
37
Q
- Which method of analysis is considered the most
reliable means of detecting mutations of BRCA,
p53, BRAF, and other genes linked to cancer?
A. FISH
B. Immunohistochemistry
C. Sequencing
D. STR analysis
A
C. Sequencing
38
Q
- An assay based on the principle of proteomics may
be used for which of the following?
A. Screening for colorectal cancer
B. Screening for lung cancer
C. Identifying malignant ovarian masses
D. Identifying malignant breast tumors
A
C. Identifying malignant ovarian masses
39
Q
- What method is used to identify maternal cell
contamination in amniocentesis and chorionic
villus samples (CVS)?
A. STR analysis
B. FISH
C. Microarray analysis
D. MicroRNA (MiRNA) analysis
A
A. STR analysis
40
Q
- What is the clinical significance of K-ras testing?
A. K-Ras mutations make tumor cells more
susceptible to chemotherapy
B. K-Ras is a tumor suppressor gene and mutations
are associated with increased lifetime risk of
malignancy
C. K-Ras mutations result in treatment resistance to
growth factor receptor inhibitors
D. K-Ras is used to identify the tissue of origin
A
C. K-Ras mutations result in treatment resistance to
growth factor receptor inhibitors
