Question 1

A patient's sample is run on cellulose acetate, and two bands are found. The first band migrates to the A region on the gel. The second band migrates to the S-D-G region on the band. What is the next step to identify the second band?

Accepted Answer

A)   Perform electrophoresis on citrate agar at pH 6.2
B)   Perform an osmotic fragility test
C)   Perform an acid elution test
D)   Do a supravital stain for Heinz bodiesE) A) and B)
F) C) and D) A

Question 2

A patient has a positive sickle solubility test. Further investigation reveals hemoglobin of 8.5 g/dL. What can be done to confirm these findings? Explain your answer.

Accepted Answer

The positive sickle solubility test can ...

Question 3

Other than hemoglobin S, name two abnormal hemoglobins that produce a positive sickle solubility test. Explain how they could be differentiated from HbS.

Accepted Answer

Hemoglobins C-Harlem and HbH have positi...

Question 4

Based on these findings, what test would be the logical next step?

Accepted Answer

A)   Bone marrow aspirate
B)   Osmotic fragility
C)   Sickle solubility test
D)   Peripheral blood smearE) A) and C)
F) B) and C)

Question 5

Based on the demographics of this patient, what disorder is suspected?

Accepted Answer

A)   Sickle cell disease
B)   Hemoglobin C disease
C)   Hemoglobin SC disease
D)   Hemoglobin E diseaseE) B) and C)
F) C) and D)

Question 6

This patient presented with swollen hands and feet. This patient suffering from what kind of crisis?

Accepted Answer

A)   Vaso-occlusive
B)   Oxidative
C)   Transfusion reaction
D)   Anaphylactic reactionE) B) and C)
F) C) and D)

Question 7

What reflex test is most appropriate for investigating these results?

Accepted Answer

A)   Hemoglobin electrophoresis and iron studies
B)   Bone marrow aspirate
C)   Vitamin B12 and folate assays
D)   Cytogenetic analysisE) All of the above
F) A) and B)

Question 8

The peripheral blood smear contains a normocytic, normochromic morphology with marked reticulocytosis. The hemoglobin solubility test is positive. What confirmatory test should follow?

Accepted Answer

A)   Bilirubin analysis
B)   Haptoglobin analysis
C)   Hemoglobin electrophoresis
D)   Bone marrow aspirationE) C) and D)
F) None of the above C

Question 9

What preoperative therapy is effective in a diagnosed sickle cell patient?

Accepted Answer

A)   Stem cell transplant
B)   Transfusion of red blood cells
C)   Hydroxyurea administration
D)   Gene therapyE) B) and C)
F) None of the above

Question 10

All of the following parameters of the complete blood count are abnormal except:

Accepted Answer

A)   Hemoglobin
B)   MCV
C)   RBCs
D)   Platelet countE) A) and B)
F) None of the above

Question 11

The strength and type of charge on a hemoglobin molecule enables the separation of hemoglobin variants by electrophoresis. What other significant factor controls this separation?

Accepted Answer

A)   Solubility of the molecule
B)   pH of the medium
C)   Heat precipitation
D)   Elevation of hemoglobin concentrationE) A) and D)
F) B) and C)

Question 12

In hemoglobin C disease, the cell's life span is decreased to what length?

Accepted Answer

A)   90-120 days
B)   7-10 days
C)   75-90 days
D)   30-55 daysE) None of the above
F) B) and D)

Question 13

Hemoglobinopathy results from a genetic abnormality of which structure within the hemoglobin molecule?

Accepted Answer

A)   Globin chain
B)   Heme
C)   Porphyrin
D)   IronE) None of the above
F) A) and D)

Question 14

Which abnormal hemoglobin is slow moving and migrates closely with hemoglobin A2 on cellulose acetate at an alkaline pH?

Accepted Answer

A)   Hemoglobin S
B)   Hemoglobin D
C)   Hemoglobin M
D)   Hemoglobin CE) B) and C)
F) A) and C) D

Question 15

The net decrease in negative charge in the hemoglobin S molecule is responsible for which laboratory finding?

Accepted Answer

A)   Increase in solubility
B)   Change in the electrophoretic mobility
C)   Increase in oxygen infinity
D)   Increase in flexibility of the red blood cellE) None of the above
F) C) and D)

Question 16

Which of the following patients would have the highest percentage of hemoglobin S?

Accepted Answer

A)   A neonate with sickle cell disease
B)   An adult with sickle cell disease
C)   An adult with sickle cell trait
D)   An adult with SC diseaseE) A) and B)
F) A) and C)

Question 17

Hemoglobin C disease has altered solubility properties similar to hemoglobin S disease. What accounts for this altered solubility?

Accepted Answer

A)   Heme iron is in the ferric form rather than ferrous form.
B)   The hemoglobin remains in the tense structure.
C)   A nonpolar amino acid is substituted for a polar amino acid.
D)   A polar amino acid is substituted near the pocket where heme binds.E) C) and D)
F) A) and B)

Question 18

What is the purpose of treating sickle cell patients with hydroxyurea?

Accepted Answer

A)   To dilute the amount of sickled red blood cells
B)   To destroy the sickling red blood cells by initiating an immune response
C)   To convert Hgb S into Hgb A
D)   To increase the level of hemoglobin F that will reduce intracellular sicklingE) A) and B)
F) A) and C)

Question 19

How is methemoglobin detected in the laboratory?

Accepted Answer

Spectral analysis at...

Question 20

Thalassemias are produced as a result of:

Accepted Answer

A)   Quantitative defects in globin chain synthesis
B)   Qualitative defects in globin chain synthesis
C)   Structural defects in heme synthesis
D)   Molecular defects in hemoglobin synthesisE) B) and C)
F) None of the above

Exam 13: Hemoglobinopathies: Qualitative Defects

A patient's sample is run on cellulose acetate, and two bands are found. The first band migrates to the A region on the gel. The second band migrates to the S-D-G region on the band. What is the next step to identify the second band?

Correct AnswerverifiedA

A patient has a positive sickle solubility test. Further investigation reveals hemoglobin of 8.5 g/dL. What can be done to confirm these findings? Explain your answer.

Correct AnswerverifiedThe positive sickle solubility test can ...View AnswerShow Answer

Other than hemoglobin S, name two abnormal hemoglobins that produce a positive sickle solubility test. Explain how they could be differentiated from HbS.

Correct AnswerverifiedHemoglobins C-Harlem and HbH have positi...View AnswerShow Answer

Based on these findings, what test would be the logical next step?

Correct AnswerverifiedShow Answer

Based on the demographics of this patient, what disorder is suspected?

Correct AnswerverifiedShow Answer

This patient presented with swollen hands and feet. This patient suffering from what kind of crisis?

Correct AnswerverifiedShow Answer

What reflex test is most appropriate for investigating these results?

Correct AnswerverifiedShow Answer

The peripheral blood smear contains a normocytic, normochromic morphology with marked reticulocytosis. The hemoglobin solubility test is positive. What confirmatory test should follow?

Correct AnswerverifiedC

What preoperative therapy is effective in a diagnosed sickle cell patient?

Correct AnswerverifiedShow Answer

All of the following parameters of the complete blood count are abnormal except:

Correct AnswerverifiedShow Answer

The strength and type of charge on a hemoglobin molecule enables the separation of hemoglobin variants by electrophoresis. What other significant factor controls this separation?

Correct AnswerverifiedShow Answer

In hemoglobin C disease, the cell's life span is decreased to what length?

Correct AnswerverifiedShow Answer

Hemoglobinopathy results from a genetic abnormality of which structure within the hemoglobin molecule?

Correct AnswerverifiedShow Answer

Which abnormal hemoglobin is slow moving and migrates closely with hemoglobin A2 on cellulose acetate at an alkaline pH?

Correct AnswerverifiedD

The net decrease in negative charge in the hemoglobin S molecule is responsible for which laboratory finding?

Correct AnswerverifiedShow Answer

Which of the following patients would have the highest percentage of hemoglobin S?

Correct AnswerverifiedShow Answer

Hemoglobin C disease has altered solubility properties similar to hemoglobin S disease. What accounts for this altered solubility?

Correct AnswerverifiedShow Answer

What is the purpose of treating sickle cell patients with hydroxyurea?

Correct AnswerverifiedShow Answer

How is methemoglobin detected in the laboratory?

Correct AnswerverifiedSpectral analysis at...View AnswerShow Answer

Thalassemias are produced as a result of:

Correct AnswerverifiedShow Answer

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A

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The positive sickle solubility test can ...
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Hemoglobins C-Harlem and HbH have positi...
View Answer

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C

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D

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Spectral analysis at...
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