THALLASSEMIAs

Question 1

What is thalassaemia? A group of inherited disorders of hemoglobin characterized by reduced or absent production of one or more globin chains

Answer 1

ineffective erythropoiesis

Question 2

What is the origin of the word “thalassaemia”? Derived from the Greek word Thalassa for “sea”; initially thought to occur only in Mediterranean populations.

Question 3

Who first described thalassaemia? Dr. Thomas Cooley in 1925 in children of Italian descent.

Question 4

What is homozygous thalassaemia major also called? Cooley’s anemia.

Question 5

Why is thalassaemia a global public health problem? It is common in tropical regions and is the most prevalent single-gene disorder worldwide.

Question 6

What are the two main classifications of thalassaemia? By the deficient globin chain (e.g.

Answer 6

α

Question 7

Which regions have the highest prevalence of β-thalassaemia? Mediterranean

Answer 7

Southeast Asia

Question 8

Which regions have the highest prevalence of α-thalassaemia? Southeast Asia

Answer 8

Eastern Mediterranean

Question 9

Why is thalassaemia common in malaria-endemic areas? Heterozygotes have a survival advantage against malaria

Answer 9

leading to high gene frequency.

Question 10

What are the clinical forms of β-thalassaemia? β-thalassaemia major

Answer 10

β-thalassaemia intermedia

Question 11

What genetic mutations cause β-thalassaemia major? Point mutations leading to genotypes such as βo/βo

Answer 11

βo/β+

Question 12

What is the main pathogenesis of β-thalassaemia major? Excess free α-chains precipitate in erythroblasts and red cells

Answer 12

damaging membranes and leading to hemolysis and ineffective erythropoiesis.

Question 13

What causes skeletal deformities in β-thalassaemia major? Extreme bone marrow hyperplasia due to anemia and hypoxia

Answer 13

causing skull and facial bone deformities.

Question 14

What causes iron overload in β-thalassaemia major? Increased iron absorption due to ineffective erythropoiesis and regular blood transfusions.

Question 15

What are the clinical features of β-thalassaemia major? Anemia

Answer 15

failure to thrive

Question 16

What is α-thalassaemia? A disorder caused by reduced or absent production of α-globin chains

Answer 16

involving up to four α-gene loci on chromosome 16.

Question 17

What are the forms of α-thalassaemia? Hb Bart’s hydrops fetalis syndrome (–/–)

Answer 17

HbH disease (–/-α)

Question 18

What is Hb Bart’s hydrops fetalis syndrome? The most severe form of α-thalassaemia

Answer 18

causing stillbirth or neonatal death due to anemia

Question 19

What laboratory features are seen in β-thalassaemia major? Low Hb

Answer 19

microcytic hypochromic anemia

Question 20

What does Hb electrophoresis show in β-thalassaemia major? Elevated HbF (10-98%)

Answer 20

variable HbA2

Question 21

What are common screening tests for thalassaemia? MCV

Answer 21

MCH

Question 22

What are key strategies for thalassaemia prevention? Health education

Answer 22

carrier screening

Question 23

What is the principle of “hyper-transfusion” in β-thalassaemia? Regular blood transfusions to maintain Hb >10 g/dL

Answer 23

preventing anemia and skeletal deformities.

Question 24

What are complications of iron overload in β-thalassaemia? Damage to the liver

Answer 24

heart

Question 25

What drugs are used for iron chelation in thalassaemia? Desferrioxamine and Deferiprone.

Question 26

What is the only curative therapy for thalassaemia? Haemopoietic stem cell transplantation (HSCT).

Question 27

What experimental therapies are under study for thalassaemia? HbF production enhancement (e.g.

Answer 27

hydroxyurea) and gene therapy to replace abnormal genes.

Question 28

What are the differential diagnoses of thalassaemia? Iron deficiency anemia

Answer 28

sickle cell disease