Q: Which of the following is the correct formula for calculating Mean Corpuscular Volume (MCV) in a CBC?

$$\text{MCV} = \frac{\text{Hematocrit} \times 10}{\text{RBC count}}$$

Question 1

Which of the following best describes the molecular basis of beta-thalassemia major?

Accepted Answer

Mutations in both β-globin genes (β⁰/β⁰) leading to absent or severely reduced β-chain production

Question 2

A patient with β-thalassemia minor will most likely show which of the following findings on hemoglobin electrophoresis?

Accepted Answer

HbA₂ (α₂δ₂) increased, typically \u003e 3.5%

Question 3

Which of the following is the correct genotype for Hemoglobin H disease in alpha thalassemia?

Accepted Answer

$$--/-\alpha$$

Question 4

In beta-thalassemia, the excess of which globin chain leads to the formation of Fessas bodies?

Accepted Answer

Excess α-globin chains

Question 5

A newborn is diagnosed with Bart’s hydrops fetalis syndrome. Which hemoglobin is predominantly formed in this condition?

Accepted Answer

Hb Bart’s (γ₄)

Question 6

Which laboratory finding is most diagnostic for β-thalassemia minor?

Accepted Answer

HbA₂ (α₂δ₂) increased, typically 4–7%

Question 7

A patient with moderate anemia, splenomegaly, and increased HbA₂ (10–50%) most likely has which form of thalassemia?

Accepted Answer

β-thalassemia intermedia

Question 8

Which chromosome contains the β-globin gene?

Accepted Answer

Chromosome 11

Question 9

What is the most likely cause of microcytic, hypochromic anemia in a patient with two missing α-globin genes?

Accepted Answer

Alpha thalassemia trait

Question 10

Which of the following hemoglobin types is absent or very low in β-thalassemia major?

Accepted Answer

HbA (α₂β₂)

Question 11

A child presents with severe anemia, jaundice, and bone deformities. Laboratory tests show HbF \u003e90% and absent HbA. What is the most likely diagnosis?

Accepted Answer

β-thalassemia major (Cooley’s anemia)

Question 12

Hemoglobin Lepore is best described as:

Accepted Answer

A structural variant resulting from unequal crossing-over between δ- and β-globin genes, producing a δβ fusion globin chain

Question 13

Which of the following is a characteristic finding in the peripheral blood smear of a patient with Hemoglobin H disease?

Accepted Answer

Target cells and Heinz-like bodies (golf ball appearance)

Question 14

In alpha thalassemia, the severity of disease is determined by:

Accepted Answer

The number of α-globin genes missing or abnormal

Question 15

Which of the following equations correctly represents the composition of adult hemoglobin A?

Accepted Answer

$$\$$alpha_2$$\$$beta_2$$

Question 16

A patient with β-thalassemia major is at risk for iron overload primarily due to:

Accepted Answer

Frequent blood transfusions

Question 17

Which of the following is a common clinical feature of β-thalassemia intermedia but not β-thalassemia major?

Accepted Answer

Moderate anemia with splenomegaly

Question 18

Which of the following is the correct formula for calculating Mean Corpuscular Volume (MCV) in a CBC?

Accepted Answer

$$	ext{MCV} = \frac{	ext{Hematocrit} 	imes 10}{	ext{RBC count}}$$

Question 19

Which of the following best explains why patients with Hemoglobin H disease experience hemolysis?

Accepted Answer

Formation of unstable β₄ tetramers that precipitate within RBCs

Thalassemia: Genetic Basis, Classification, and Clinical Features

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