Knowledge Burst Unit 10

Question 1

The qualitative hemoglobinpathies cause disease by producing hemoglobin chains that are:

Answer 1

Structurally altered

Question 2

Which of the following hemoglobinopathies is most common?

Answer 2

Sickle Cell diseases

Question 3

What clinical feature of sickle cell diseases accounts for the highest number of hospital admissions?

Answer 3

Vaso-occusion

Question 4

Sickle cell disease (SCD) is found in individuals descended from ancestors from all of the following places except:
- Africa
- Middle East
- Mediterranean
- Scandinavia

Answer 4

Scandinavia

Question 4

What percentage of African Americans have heterozygous sickle cell trait?

Answer 4

8%

Question 5

Which of the following would be an unusual finding in the blood smear of an adult with sickle cell disease (SCD) crisis?

Answer 5

Heinz bodies

Question 6

What is the probable etiologic association between malaria and sickle cell trait?

Answer 6

Sickle gene offers some protection against malaria

Question 7

Which of the following would be unexpected in homozygous hemoglobin S?

Answer 7

Hemoglobin A

Question 8

A patient has target cells and a positive tube solubility test. This patient probably:

Answer 8

Has either sickle cell anemia or trait

Question 9

What is the best test to confirm the diagnosis of a patient presenting with target cells and a positive tube solubility test?

Answer 9

Hemoglobin electrophoresis

Question 10

What is the basic hemoglobin defect in the thalassemias?

Answer 10

A structurally normal globin chain is absent or produced at lower levels

Question 11

Which of the following is the normal approximate percentage of hemoglobins in adults?
a2b2, a2d2, a2g2

Answer 11

Hemoglobin A (a2b2) = 96%
Hemoglobin A2 (a2d2) = 2%
Hemoglobin F (a2g2) = 2%

Question 12

All of the following can distinguish b-thalassemia minor from major

Answer 12

Clinical findings, hemoglobin concentration, and presence of HbA