Thalassaemia

Question 1

What is thalassaemia due to?

Answer 1

Genetic defect in the protein chains that make up haemoglobin

Question 2

What does a defect in the alpha-globin chains leads to?

Answer 2

Alpha thalassaemia.

Question 3

What does a defect in the beta-globin chains leads to?

Answer 3

Beta Thalassaemia

Question 4

What type of conditions are alpha and beta thalassaemia?

Answer 4

Autosomal recessive

Question 5

What are the potential signs and symptoms of thalassaemia?

Answer 5

• Microcytic anaemia (low mean corpuscular volume)
• Fatigue
• Pallor
• Jaundice
• Gallstones
• Splenomegaly
• Poor growth and development
• Pronounced forehead and malar eminences

Question 6

How can thalassaemia be diagnosed?

Answer 6

Full blood count
Haemoglobin electrophoresis
DNA testing

Question 7

What might a full blood count show?

Answer 7

Microcytic anaemia

Question 8

What might haemoglobin electrophoresis show?

Answer 8

Globulin abnormalities

Question 9

What might DNA testing show?

Answer 9

Genetic abnormalities

Question 10

What is alpha thalassaemia due to?

Answer 10

Due to a deficiency of alpha-globin chains.

Question 11

Where are the 2 alpha-globulin genes located?

Answer 11

Chromosome 16

Question 12

What is the clinical severity of alpha thalassaemia due to?

Answer 12

The number of alpha globulin alleles affected

Question 13

If 1 or 2 alpha globulin alleles are affected, what would the blood picture be?

Answer 13

The blood picture would be hypochromic and microcytic

Question 14

What would the Hb levels be if the 1 of 2 alpha globulin alleles are affected?

Answer 14

The Hb level would be typically normal

Question 15

If 3 alpha globulin alleles are affected, what would the blood picture be?

Answer 15

Hypochromic microcytic anaemia with splenomegaly.

Question 16

What disease is Hypochromic microcytic anaemia with splenomegaly known as?

Answer 16

Hb H disease

Question 17

If all 4 alpha globulin alleles are affected, what can occur?

Answer 17

Death in utero

Question 18

What is the management of alpha thalassaemia?

Answer 18

Monitoring the full blood count
Monitoring for complications
Blood transfusions
Splenectomy may be performed

Question 19

What can be curative for alpha thalassaemia?

Answer 19

Bone marrow transplant

Question 20

What is Beta thalassaemia caused by?

Answer 20

Defects in beta-globin chains.

Question 21

What chromosome has the gene coding for beta-globulin?

Answer 21

Chromosome 11

Question 22

What can the defect in the beta-globulin chains consist of?

Answer 22

• abnormal copies that retain some function

* deletion genes where there is no function in the beta-globin protein at all.

Question 23

What can beta thalassaemia be split into?

Answer 23

• Thalassaemia minor
• Thalassaemia intermedia
• Thalassaemia major

Question 24

What is beta thalassaemia minor due to?

Answer 24

Patients are carriers of an abnormal beta globin gene and one normal gene.

Question 25

What does beta thalassaemia minor cause?

Answer 25

It causes a mild microcytic anaemia

Question 26

What is the management of patients with beta thalassaemia minor?

Answer 26

Monitoring and no active treatment.

Question 27

What is beta thalassaemia intermedia due to?

Answer 27

Patients have two abnormal copies of the beta-globin gene. | Either two defective genes or one defective gene and one deletion gene.

Question 28

What does beta thalassaemia intermedia cause?

Answer 28

More severe microcytic anaemia

Question 29

What is the management of patients with beta thalassaemia intermedia ?

Answer 29

Monitoring | Occasional blood transfusions

Question 30

If a patient with beta thalassaemia intermedia requires blood transfusions, which might they also require and why?

Answer 30

Iron chelation to prevent iron overload.

Question 31

What is beta thalassaemia major due to?

Answer 31

Patients are homozygous for the deletion genes. | They have no functioning beta-globin genes at all.

Question 32

What is the most severe form of beta thalassaemia?

Answer 32

Beta thalassaemia major

Question 33

What are the features of beta thalassaemia major?

Answer 33

* Severe anaemia | * Failure to thrive in early childhood.

Question 34

When does beta thalassaemia major tend to present?

Answer 34

3-6 months | when fetal haemoglobin starts to become adult haemoglobin

Question 35

How does beta thalassaemia major present?

Answer 35

* Severe microcytic anaemia * Splenomegaly * Bone deformities

Question 36

What can be curative for beta thalassaemia major?

Answer 36

Bone marrow transplant

Question 37

What is the management of beta thalassaemia major?

Answer 37

* Regular transfusions * Iron chelation * Splenectomy

Question 38

What happens in thalassaemia?

Answer 38

The red blood cells are more fragile and break down more easily. The spleen acts as a sieve to filter the blood and remove older blood cells

Question 39

What do patients with thalassaemia need to have checked and what for ?

Answer 39

Need to have their serum ferritin levels monitored to check for iron overload

Question 40

How can thalassaemia present with bone deformities?

Answer 40

The bone marrow expands to produce extra red blood cells to compensate for the chronic anaemia. This causes a susceptibility to fractures and prominent features such as a pronounced forehead and malar eminences (cheekbones).

Question 41

How can thalassaemia present with splenomegaly?

Answer 41

The spleen collects all the destroyed red blood cells and swells, resulting in splenomegaly.

Question 42

How can thalassaemia result in iron overload?

Answer 42

Faulty creation of red blood cells Recurrent transfusions Increased absorption of iron in response to the anaemia.

Question 43

What is the management of iron overload in thalassaemia?

Answer 43

Limiting transfusions | Iron chelation.

Question 44

How can iron overload in thalassaemia present?

Answer 44

* Fatigue * Liver cirrhosis * Infertility and impotence * Heart failure * Arthritis * Diabetes * Osteoporosis and joint pain

Question 45

What would happen if beta thalassaemia was left untreated?

Answer 45

Person wouldn't live longer than about 10 years old