THALASSEMIA

Question 1

• are a diverse group of inherited disorders caused by genetic mutations that reduce or prevent the synthesis of one or more of the globin chains of the hemoglobin tetramer

Answer 1

THALASSEMIAS

Question 2

Pathophysiology of Thalassemia

Answer 2

🩸reduced or absent production of a particular globin chain
🩸 An unequal production of the α/β chains causing an imbalance in the α/β chain ratio

Question 3

disorders of reduced globin chain production arising from the β-globin gene cluster on chromosome 11 - most commonly by point mutation

Answer 3

β-THALASSEMIA

Question 4

• skull radiographs may demonstrate a typical “hair on end”appearance
• typical facies occur: prominence of the forehead, cheekbones, and upper jaw

Answer 4

β-THALASSEMIA

Question 5

Four categories: of β-THALASSEMIA

Answer 5

a. β-thalassemia silent carrier
b. β-thalassemia minor
c. β-thalassemia major
d. β-thalassemia intermedia

Question 6

• no hematologic abnormalities

Answer 6

β-thalassemia silent carrier

Question 7

• results when one β-globin gene is affected by a mutation that decreases or abolishes its expression, whereas the other β-globin gene is normal
• microcytic, hypochromic RBCs, slightly increased reticulocyte count, poikilocytosis (target cells, elliptocytes), inclusions (basophilic stipplings)

Answer 7

β-thalassemia minor

Question 8

• pronounced or complete reduction or absence of β-chain production
• characterized by severe anemia that requires regular transfusion therapy
• microcytic, hypochromic RBCs, poikilocytosis (target cells, teardrop cells, elliptocytes), inclusions (basophilic stipplings, Howell-Jolly bodies, and Pappenheimer bodies), reticulocytosis

Answer 8

β-thalassemia major

Question 9

term used to describe anemia that is more severe than β-thalassemia minor but does not require regular transfusion

Answer 9

β-thalassemia intermedia

Question 10

• large deletions involving the α1- and/or α2-globin genes

Answer 10

α- THALASSEMIA

Question 11

Four categories: α- THALASSEMIA

Answer 11

Silent carrier state
α-thalassemia minor
α-thalassemia major
Bart’s hemoglobin

Question 12

• results in the absence of all α-chain production and usually results in death in utero or shortly after birth
• Hb Bart (γ4) is the predominant hemoglobin

Answer 12

Bart’s hemoglobin

Question 13

• deletion of three α-globin genes
• characterized by the accumulation of excess unpaired β chains

Answer 13

α-thalassemia major

Question 14

• Hb H is vulnerable to oxidation and gradually precipitates in the circulating RBCs to form inclusion bodies of denature hemoglobin
• cells are often described as “golf balls”or “raspberries”

Answer 14

α-thalassemia major

Question 15

• deletion of two α-globin genes
• exists in two forms: Homozygous (-α/-α) or heterozygous (–/αα) - microcytic, hypochromic RBCs

Answer 15

α-thalassemia minor

Question 16

deletion of one α-globin genes (-α/αα)

Answer 16

Silent carrier state

Question 17

Diagnosis of Thalassemia: Physical examination:

Answer 17

-pallor
- jaundice
- splenomegaly
- skeletal deformities

Question 18

Diagnosis of Thalassemia: CBC

Answer 18

microcytic, hypochromic anemia

• RBC count disproportionate to the degree of anemia - elevated RDW

Question 19

PBS in Thalassemia

Answer 19

-target cells, elliptocytes
- polychromasia
- basophilic stipplings, Howell-Jolly bodies, Pappenheimer bodies

Question 20

Supravital staining: Thalassemia

Answer 20

• BCB or new methylene blue (induce precipitation of unstable Hb)
• Hb H inclusions appear as small, multiple, irregularly shaped greenish blue bodies that are uniformly distributed throughout the RBC

Question 21

Quantitation of Hb F: Thalassemia

Answer 21

a. Betke Method of Alkali Denaturation
b. Singer Method of Alkali Denaturation
c. Acid Elution Test