Thalassemias Flashcards
1
Q
- The thalassemias are caused by:
a. Structurally abnormal hemoglobins
b. Absent or defective synthesis of a polypeptide chain in
hemoglobin
c. Excessive absorption of iron
d. Abnormal or defective protoporphyrin synthesis
A
b. Absent or defective synthesis of a polypeptide chain in
hemoglobin
2
Q
- Thalassemia is more prevalent in individuals from areas
along the tropics because it confers:
a. Heat resistance to those heterozygous for a thalassemia gene
b. Selective advantage against tuberculosis
c. Selective advantage against malaria
d. Resistance to mosquito bites
A
c. Selective advantage against malaria
3
Q
- The hemolytic anemia associated with the thalassemias is
due to:
a. Imbalance of globin chain synthesis
b. Microcytic, hypochromic cells
c. Ineffective erythropoiesis caused by immune factors
d. Structurally abnormal hemoglobin
A
a. Imbalance of globin chain synthesis
4
Q
- b-Thalassemia minor (heterozygous) usually exhibits:
a. Increased Hb Constant Spring
b. 50% Hb F
c. No Hb A
d. Increased Hb A2
A
d. Increased Hb A2
5
Q
- RBC morphologic features in b-thalassemia would most
likely include:
a. Microcytes, hypochromia, target cells, elliptocytes, stippled
cells
b. Macrocytes, acanthocytes, target cells, stippled cells
c. Microcytes, sickle cells
d. Macrocytes, hypochromia, target cells, stippled cells
A
a. Microcytes, hypochromia, target cells, elliptocytes, stippled
cells
6
Q
- The predominant hemoglobin present in b0-thalassemia
major is:
a. Hb A
b. Hb A2
c. Hb F
d. Hb C
A
c. Hb F
7
Q
- Heterozygous HPFH is characterized by:
a. 10% to 35% Hb F with normal RBC morphology
b. 100% Hb F with slightly hypochromic, microcytic cells
c. A decreased amount of Hb F with normal RBC morphology
d. 5% to 15% Hb F with hypochromic, macrocytic cells
A
a. 10% to 35% Hb F with normal RBC morphology
8
Q
- Hb H is composed of:
a. Two a and two b chains
b. Two e and two g chains
c. Four b chains
d. Four g chains
A
c. Four b chains
9
Q
- Hb Bart is composed of:
a. Two a and two b chains
b. Two e and two g chains
c. Four b chains
d. Four g chains
A
d. Four g chains
10
Q
- When one a gene is deleted (a–/aa), a patient has:
a. Normal hemoglobin levels
b. Mild anemia (hemoglobin range 9 to 11 g/dL)
c. Moderate anemia (hemoglobin range 7 to 9 gm/dL)
d. Marked anemia requiring regular transfusions
A
a. Normal hemoglobin levels
11
Q
- In which part of the world is the a gene mutation causing
Hb Bart hydrops fetalis (– –/– –) most common?
a. Northern Africa
b. Mediterranean
c. Middle East
d. Southeast Asia
A
d. Southeast Asia
12
Q
- The condition Hb S-b0-thalassemia has a clinical course
that resembles:
a. Sickle cell trait
b. Sickle cell anemia
c. b-Thalassemia minor
d. b-Thalassemia major
A
b. Sickle cell anemia
13
Q
- Hb H inclusions in a supravital stain preparation appear as:
a. A few large, blue, round bodies in the RBCs with aggregated reticulum
b. Uniformly stained blue cytoplasm in the RBC
c. Small, evenly distributed, greenish-blue granules that
pit the surface of RBCs
d. Uniform round bodies that adhere to the RBC membrane
A
c. Small, evenly distributed, greenish-blue granules that
14
Q
- Which of the following laboratory findings is inconsistent
with b-thalassemia minor?
a. A slightly elevated RBC count and marked microcytosis
b. Target cells and basophilic stippling on the peripheral
blood film
c. Hemoglobin level of 10 to 13 g/dL
d. Elevated MCHC and spherocytic RBCs
A
d. Elevated MCHC and spherocytic RBCs
15
Q
- A 4-month-old infant of Asian heritage is seen for a
well-baby check. Because of pallor, the physician suspects
anemia and orders a CBC. The RBC count is 4.5 3 109/L,
Hb concentration is 10 g/dL, and MCV is 77 fL, with microcytosis, hypochromia, poikilocytosis, and mild polychromasia
noted on the peripheral blood film. These findings should
lead the physician to suspect:
a. b-Thalassemia major
b. a-Thalassemia silent carrier state
c. Iron deficiency anemia
d. Homozygous a-thalassemia (– –/– –)
A
c. Iron deficiency anemia
