11. Hemolytic Anemias: Intracorpuscular Defects: III. The Hemoglobinopathies

Question 1

1. Which of the following is not a characteristic of hemo-globinopathies?
   a. Abnormal hemoglobins are synthesized.
   b. Result from inherited abnormalities or genetic mutations.
   c. All are manifested in clinically significant conditions.
   d. Result in a defect in structural integrity or function of the hemoglobin molecule.

Answer 1

c. All are manifested in clinically significant conditions.

Question 2

2. Which of the following are used in the nomenclature system for abnormal hemoglobins?
   a.Capital letters
   b.Names of places
   c.Names of chains and substitutions
   d.All of the above

Answer 2

d.All of the above

Question 3

3. What is the amino acid substitution found in sickle cell anemia?

a. Substitution of valine for glutamic acid in the sixth position from the NH2-terminal β chain
b.Substitution of lysine for glutamic acid in the sixth position from the NH2-terminal β chain
c. Substitution of lysine for glutamic acid in the 26th position from the NH2-terminal β chain
d. Substitution of valine for glutamic acid in the 121st position from the NH2-terminal β chain

Answer 3

a. Substitution of valine for glutamic acid in the sixth position from the NH2-terminal β chain

Question 4

4. What factors contribute to the sickling of RBCs?
   a. Increase in pH and oxygenation
   b. Decrease in pH and oxygenation, and dehydration
   c. Increase in pH and decrease in oxygenation
   d. Decrease in dehydration and increase in pH and oxygenation

Answer 4

b. Decrease in pH and oxygenation, and dehydration

Question 5

5. Which of the following are crises associated with sickle cell anemia?
   a. Aplastic crisi with low reticulocyte count, and infections
   b.Hemolytic crisis with splenic sequestration, decreased hemoglobin and hematocrit, increased reticulocyte count,and jaundice
   c. Vaso-occlusive or painful crises with severe pain,tissue damage, and necrosis
   d.All of the above

Answer 5

d.All of the above

Question 6

6. What are the therapeutic goals in the treatment of sickle cell anemia?

a. Decrease microvascular entrapment of sickled cells or change the volume of RBCs
b. Modify oxygen affinity or solubility of sickle hemo-globin
c.Increase production of fetal hemoglobin
d.All of the above

Answer 6

d.All of the above

Question 7

7.What is the amino acid substitution found in HbC disease?

a. Substitution of valine for glutamic acid in the sixth position from the NH2-terminal β chain
b.Substitution of lysine for glutamic acid in the sixth position from the NH2-terminal β chain
c. Substitution of lysine for glutamic acid in the 26th position from the NH2-terminal β chain
d. Substitution of valine for glutamic acid in the 121st position from the NH2-terminal β chain

Answer 7

b.Substitution of lysine for glutamic acid in the sixth position from the NH2-terminal β chain

Question 8

8.Which of the following is not true for HbC disease?

a.Mild anemia
b.Numerous target cells
c.Crystals in red cells
d.HbC can be separated from other hemoglobins at an alkaline pH

Answer 8

d.HbC can be separated from other hemoglobins at an alkaline pH

Question 9

9.Which finding would be most useful in establishing a di-agnosis of HbSC disease?

a.Target cells and sickled cells on peripheral blood smear
b.Severe anemia: Increased reticulocyte count
c. Hemoglobin electrophoresis at alkaline pH
d. RBC indices

Answer 9

c. Hemoglobin electrophoresis at alkaline pH

Question 10

10.Which of the following is a cause of methemoglobinemia?
a.HbM variants
b.NADH-diaphorase deficiency
c.Toxic substances
d.All of the above

Answer 10

d.All of the above