THALLASSEMIAs

Question 1

What is thalassaemia?

Answer 1

A group of inherited disorders of hemoglobin characterized by reduced or absent production of one or more globin chainsineffective erythropoiesis

Question 2

What is the origin of the word “thalassaemia”?

Answer 2

Derived from the Greek word Thalassa for “sea”; initially thought to occur only in Mediterranean populations.

Question 3

Who first described thalassaemia?

Answer 3

Dr. Thomas Cooley in 1925 in children of Italian descent.

Question 4

What is homozygous thalassaemia major also called?

Answer 4

Cooley’s anemia.

Question 5

Why is thalassaemia a global public health problem?

Answer 5

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?

Answer 6

By the deficient globin chain (e.g. α

Question 7

Which regions have the highest prevalence of β-thalassaemia?

Answer 7

Mediterranean Southeast Asia

Question 8

Which regions have the highest prevalence of α-thalassaemia?

Answer 8

Southeast Asia Eastern Mediterranean

Question 9

Why is thalassaemia common in malaria-endemic areas?

Answer 9

Heterozygotes have a survival advantage against malaria leading to high gene frequency.

Question 10

What are the clinical forms of β-thalassaemia?

Answer 10

β-thalassaemia major β-thalassaemia intermedia

Question 11

What genetic mutations cause β-thalassaemia major?

Answer 11

Point mutations leading to genotypes such as βo/βo
βo/β+

Question 12

What is the main pathogenesis of β-thalassaemia major?

Answer 12

Excess free α-chains precipitate in erythroblasts and red cells damaging membranes and leading to hemolysis and ineffective erythropoiesis.

Question 13

What causes skeletal deformities in β-thalassaemia major?

Answer 13

Extreme bone marrow hyperplasia due to anemia and hypoxia causing skull and facial bone deformities.

Question 14

What causes iron overload in β-thalassaemia major?

Answer 14

Increased iron absorption due to ineffective erythropoiesis and regular blood transfusions.

Question 15

What are the clinical features of β-thalassaemia major?

Answer 15

Anemia failure to thrive

Question 16

What is α-thalassaemia?

Answer 16

A disorder caused by reduced or absent production of α-globin chains involving up to four α-gene loci on chromosome 16.

Question 17

What are the forms of α-thalassaemia?

Answer 17

Hb Bart’s hydrops fetalis syndrome (–/–) HbH disease (–/-α)

Question 18

What is Hb Bart’s hydrops fetalis syndrome?

Answer 18

The most severe form of α-thalassaemia causing stillbirth or neonatal death due to anemia

Question 19

What laboratory features are seen in β-thalassaemia major?

Answer 19

Low Hb
microcytic hypochromic anemia

Question 20

What does Hb electrophoresis show in β-thalassaemia major?

Answer 20

Elevated HbF (10-98%) variable HbA2

Question 21

What are common screening tests for thalassaemia?

Answer 21

MCV MCH

Question 22

What are key strategies for thalassaemia prevention?

Answer 22

Health education carrier screening

Question 23

What is the principle of “hyper-transfusion” in β-thalassaemia?

Answer 23

Regular blood transfusions to maintain Hb >10 g/dL preventing anemia and skeletal deformities.

Question 24

What are complications of iron overload in β-thalassaemia?

Answer 24

Damage to the liver heart

Question 25

What drugs are used for iron chelation in thalassaemia?

Answer 25

Desferrioxamine and Deferiprone.

Question 26

What is the only curative therapy for thalassaemia?

Answer 26

Haemopoietic stem cell transplantation (HSCT).

Question 27

What experimental therapies are under study for thalassaemia?

Answer 27

HbF production enhancement (e.g. hydroxyurea) and gene therapy to replace abnormal genes.

Question 28

What are the differential diagnoses of thalassaemia?

Answer 28

Iron deficiency anemia sickle cell disease