Thalassaemia

Question 1

How many globin chains are in haemoglobin and which types?

Answer 1

2 alpha
2 beta

Question 2

What type of genetic condition is Thalassaemia? E.g. dominant

Answer 2

Autosomal recessive

Question 3

What causes haemolytic anaemia in Thalassaemia?

Answer 3

the red blood cells are more fragile and break down easily, causing haemolytic anaemia.

Question 4

What are the universal features of Thalassaemia? (7)

Answer 4

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

Question 5

What is seen on an fbc in Thalassaemia? (2)

Answer 5

Microcytic anaemia
Some severe cases may have raised ferritin from iron overload

Question 6

What test is used to diagnose globin abnormalities such as Thalassaemia?

Answer 6

Haemoglobin electrophoresis

Question 7

Who is offered screening tests for Thalassaemia?

Answer 7

All pregnant women

Question 8

What can cause iron overload in Thalassaemia? (2)

Answer 8

• Increased iron absorption in the gastrointestinal tract
• Blood transfusions

Question 9

What symptoms and complications does iron overload cause in Thalassaemia? (6)

Answer 9

○ Liver cirrhosis
○ Hypogonadism
○ Hypothyroidism
○ Heart failure
○ Diabetes
○ Osteoporosis

Question 10

What is the management of iron over load in Thalassaemia? (2)

Answer 10

Limiting transfusions
Iron chelation

Question 11

Where are the genes that code for alpha globin found?

Answer 11

Chromosome 16

Question 12

What are the types of alpha Thalassaemia and what degree of anaemia do each get? (3)

Answer 12

Carrier - asymptomatic
Haemoglobin H disease - moderate anaemia
Alpha Thalassaemia major - intrauterine death due to severe fatal anaemia

Question 13

What is involved in the management of alpha Thalassaemia? (4)

Answer 13

• Monitoring
• Blood transfusions
• Splenectomy may be performed
• Bone marrow transplant can be curative

Question 14

Where is the gene coding for beta Thalassaemia found?

Answer 14

Chromosome 11

Question 15

What are the 2 types of gene defects that can occur in the beta globin gene?

Answer 15

Abnormal copies = can retain some function
Deletion genes = no fucntiin

Question 16

What are the 3 types of beta Thalassaemia?

Answer 16

• Thalassaemia minor
• Thalassaemia intermedia
• Thalassaemia major

Question 17

What types of genes do people with Thalassaemia minor/trait have?

Answer 17

Carries
Have 1 abnormal and 1 normal gene

Question 18

What are the symptoms of Thalassaemia minor/trait?

Answer 18

Mild microcytic anaemia

Question 19

What type of gene copies do people with Thalassaemia intermedia carry?

Answer 19

2 abnormal copies either:
• Two defective genes
• One defective gene and one deletion gene

Question 20

What are the symptoms of Thalassaemia intermedia?

Answer 20

Significant microcytic anaemia

Question 21

What is the management of Thalassaemia intermedia? (3)

Answer 21

Monitoring
Blood transfusions
Iron chelation to prevent iron overload

Question 22

What gene types do people with Thalassaemia major carry?

Answer 22

Homozygous for the deletion genes
No functioning beta globin chains

Question 23

What does Thalassaemia major present with? (2)

Answer 23

Severe anaemia
Failure to thrive in early childhood

Question 24

What happens to bone marrow in Thalassaemia major?

Answer 24

The bone marrow is under so much strain to produce extra red blood cells to compensate for the chronic anaemia that it expands enough to increase the risk of fractures and change the patient’s appearance.

Question 25

What bone changes are seen in Thalassaemia major? (4)

Answer 25

• Frontal bossing (prominent forehead)
• Enlarged maxilla (prominent cheekbones)
• Depressed nasal bridge (flat nose)
• Protruding upper teeth

Question 26

What is the management of beta Thalassaemia major? (4)

Answer 26

Regular blood transfusions
Iron chelation
Splenectomy
Bone marrow transplant can be curative