Question 1

Which molecular technique is useful in monitoring the amount of pathogen-specific nucleic acids in patients with an infectious disease?

Accepted Answer

qPCR (quantitative polymerase chain reaction) is a highly sensitive molecular technique used to amplify and quantify specific DNA or RNA sequences. It can detect and monitor the amount of pathogen-specific nucleic acids in patient samples, making it a valuable tool in diagnosing and managing infectious diseases. ASO (allele-specific oligonucleotide) is a technique used to detect specific single nucleotide polymorphisms, while FISH (fluorescence in situ hybridization) is used to detect and locate specific nucleic acid sequences in cells or tissues. DNA amplification and sequencing is a broader term that refers to techniques such as PCR and next-generation sequencing, which can be used for a variety of molecular applications beyond pathogen detection.

Question 2

Inherited diseases are characterized by:

Accepted Answer

Inherited diseases are the result of genetic defects that are generally present in all tissues of the patient's body since they are inherited from their parents. Therefore, option D is the most appropriate choice. Option A is not correct since sex-linked mutations can be expressed in both males and females, and not just females. Option B is not correct as acquired mutations are not inherited and are not present in all tissues of the body. Option C is not correct since inherited diseases are those that run in families and have a correlation between genotype and disease status among family members.

Question 3

Which of the following assays would be most appropriate for monitoring minimal residual disease?

Accepted Answer

qPCR (quantitative polymerase chain reaction) is the most sensitive and specific method for detecting and monitoring minimal residual disease in patients with leukemia or lymphoma. qPCR can quantitatively measure the number of cancer cells present in a sample, making it an ideal method for identifying patients who may require additional treatment or closer monitoring. Karyotyping and Southern blot analysis are less sensitive and less specific than qPCR, and are more useful for detecting large-scale chromosomal abnormalities or gene rearrangements.

Question 4

The use of a labeled probe to detect and localize specific RNA or DNA sequences in tissue samples describes which of the following techniques:

Accepted Answer

The technique of using a labeled probe to detect and localize specific RNA or DNA sequences in tissue samples is called FISH (Fluorescence In Situ Hybridization). This method allows us to visualize specific genes or regions of the genome in cells and tissues under fluorescence microscopy. This technique is commonly used in research and diagnostic applications, including cytogenetics, cancer biology, developmental biology, and microbiology. A, B, and C are all molecular biology techniques but not specifically used for the detection and localization of specific RNA or DNA sequences like FISH.

Question 5

Give the advantages of PCR over Southern blot and advantages of Southern blot over PCR.

Accepted Answer

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Question 6

Which of the following is associated with chronic myelogenous leukemia?

Accepted Answer

Chronic myelogenous leukemia is associated with the BCR/ABL1 fusion gene, which results from a translocation between chromosomes 9 and 22.

Question 7

Which of the following molecular techniques is useful in detecting the point mutations in a suspected hemoglobinopathy:

Accepted Answer

DNA amplification and sequencing is the best choice as it allows for the detection of specific point mutations by amplifying and sequencing the DNA of the suspected hemoglobinopathy. qPCR and RT-PCR are useful for quantifying gene expression but do not necessarily detect specific mutations. High-resolution melt curve analysis can detect subtle changes in DNA but may not be as specific as sequencing.

Question 8

A 23-year-old female is admitted to the local hospital with a deep vein thrombosis.In addition to initial laboratory workup,which of the following should be investigated as possible causes of the DVT?

Accepted Answer

FV and prothrombin mutations are known genetic risk factors for deep vein thrombosis. PCR for sickle cell mutation is not typically associated with DVT and BCR/ABL1 and TCR gene mutations are not related to clotting disorders.

Question 9

What is the definition of allele?

Accepted Answer

Allele is defined as a form of a gene that is responsible for a variation of a particular trait. In sexually reproducing organisms, individuals inherit two alleles for each gene, one from each parent. Hence, option B is the correct definition of an allele. Options A, C, and D are incorrect as they define other important concepts in genetics, such as DNA, RNA, and proteins, but not alleles.

Question 10

Explain the central dogma of molecular biology using proper nomenclature.Define each phase.

Accepted Answer

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Question 11

Explain the impact of a positive test for HTLV-1 in a lymphoma patient.

Accepted Answer

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Question 12

A Hodgkin lymphoma patient is admitted for treatment.What would be the benefit in performing an EBV-DNA test on him?

Accepted Answer

EBV-DNA levels in patients with Hodgkin lymphoma can be used to monitor the efficacy of treatment, as changes in these levels can reflect the tumor burden and response to therapy.

Question 13

Name and compare two molecular methods used to detect mutations associated with sickle cell disease.

Accepted Answer

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Question 14

In reference to detecting minimal residual disease,which of the following is true?

Accepted Answer

qPCR is a highly sensitive technique that can detect low levels of tumor burden, making it well-suited for detecting minimal residual disease. PCR, karyotyping, and Southern blot analysis are less sensitive than qPCR and may not be able to detect very low levels of disease. Karyotyping is typically used to detect chromosomal abnormalities and may not be sensitive enough to detect a 0.1% tumor burden. Southern blot analysis can detect specific DNA sequences, but its sensitivity and specificity depend on the quality of the sample and the probe used.

Question 15

Which of the following methods would be most useful for identifying point mutations anywhere in the DNA segment?

Accepted Answer

PCR amplifies a specific DNA segment, but it does not provide information about the sequence of the DNA. Southern blot analysis and FISH can only identify mutations in specific regions of the DNA. DNA sequencing, on the other hand, can identify point mutations anywhere in the DNA segment by determining the exact nucleotide sequence.

Question 16

A multiplex reaction that targets conserved regions within the variable (V),diversity (D),and joining (J)regions of the immunoglobulin heavy chain can be used to determine clonality in which neoplasm?

Accepted Answer

The multiplex reaction targeting conserved regions within the V, D, and J regions of the immunoglobulin heavy chain is a commonly used method for determining clonality in B-cell leukemia/lymphoma. This assay is specific for B-cells and can identify the clonal expansion of malignant B-cells. CML, AML, and Human T-lymphotropic virus type 1 are not B-cell neoplasms and are not typically evaluated using this assay.

Question 17

Explain why molecular testing is essential not only in identifying disorders,such as cancer,but also during the course of a disease.

Accepted Answer

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Question 18

Minimal residual disease testing is a molecular application for which hematopathology?

Accepted Answer

Minimal residual disease testing is most commonly used in the context of leukemia and lymphoma to monitor for residual cancer cells after treatment.

Quiz 42: Molecular Analysis of Hematologic Diseases