Thalassaemia Flashcards

1
Q

What is thalassaemia due to?

A

Genetic defect in the protein chains that make up haemoglobin

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2
Q

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

A

Alpha thalassaemia.

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3
Q

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

A

Beta Thalassaemia

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4
Q

What type of conditions are alpha and beta thalassaemia?

A

Autosomal recessive

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5
Q

What are the potential signs and symptoms of thalassaemia?

A
  • Microcytic anaemia (low mean corpuscular volume)
  • Fatigue
  • Pallor
  • Jaundice
  • Gallstones
  • Splenomegaly
  • Poor growth and development
  • Pronounced forehead and malar eminences
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6
Q

How can thalassaemia be diagnosed?

A

Full blood count
Haemoglobin electrophoresis
DNA testing

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7
Q

What might a full blood count show?

A

Microcytic anaemia

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8
Q

What might haemoglobin electrophoresis show?

A

Globulin abnormalities

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9
Q

What might DNA testing show?

A

Genetic abnormalities

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10
Q

What is alpha thalassaemia due to?

A

Due to a deficiency of alpha-globin chains.

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11
Q

Where are the 2 alpha-globulin genes located?

A

Chromosome 16

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12
Q

What is the clinical severity of alpha thalassaemia due to?

A

The number of alpha globulin alleles affected

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13
Q

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

A

The blood picture would be hypochromic and microcytic

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14
Q

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

A

The Hb level would be typically normal

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15
Q

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

A

Hypochromic microcytic anaemia with splenomegaly.

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16
Q

What disease is Hypochromic microcytic anaemia with splenomegaly known as?

A

Hb H disease

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17
Q

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

A

Death in utero

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18
Q

What is the management of alpha thalassaemia?

A

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

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19
Q

What can be curative for alpha thalassaemia?

A

Bone marrow transplant

20
Q

What is Beta thalassaemia caused by?

A

Defects in beta-globin chains.

21
Q

What chromosome has the gene coding for beta-globulin?

A

Chromosome 11

22
Q

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

A
  • abnormal copies that retain some function

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

23
Q

What can beta thalassaemia be split into?

A
  • Thalassaemia minor
  • Thalassaemia intermedia
  • Thalassaemia major
24
Q

What is beta thalassaemia minor due to?

A

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

25
Q

What does beta thalassaemia minor cause?

A

It causes a mild microcytic anaemia

26
Q

What is the management of patients with beta thalassaemia minor?

A

Monitoring and no active treatment.

27
Q

What is beta thalassaemia intermedia due to?

A

Patients have two abnormal copies of the beta-globin gene.

Either two defective genes or one defective gene and one deletion gene.

28
Q

What does beta thalassaemia intermedia cause?

A

More severe microcytic anaemia

29
Q

What is the management of patients with beta thalassaemia intermedia ?

A

Monitoring

Occasional blood transfusions

30
Q

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

A

Iron chelation to prevent iron overload.

31
Q

What is beta thalassaemia major due to?

A

Patients are homozygous for the deletion genes.

They have no functioning beta-globin genes at all.

32
Q

What is the most severe form of beta thalassaemia?

A

Beta thalassaemia major

33
Q

What are the features of beta thalassaemia major?

A
  • Severe anaemia

* Failure to thrive in early childhood.

34
Q

When does beta thalassaemia major tend to present?

A

3-6 months

when fetal haemoglobin starts to become adult haemoglobin

35
Q

How does beta thalassaemia major present?

A
  • Severe microcytic anaemia
  • Splenomegaly
  • Bone deformities
36
Q

What can be curative for beta thalassaemia major?

A

Bone marrow transplant

37
Q

What is the management of beta thalassaemia major?

A
  • Regular transfusions
  • Iron chelation
  • Splenectomy
38
Q

What happens in thalassaemia?

A

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

39
Q

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

A

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

40
Q

How can thalassaemia present with bone deformities?

A

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).

41
Q

How can thalassaemia present with splenomegaly?

A

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

42
Q

How can thalassaemia result in iron overload?

A

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

43
Q

What is the management of iron overload in thalassaemia?

A

Limiting transfusions

Iron chelation.

44
Q

How can iron overload in thalassaemia present?

A
  • Fatigue
  • Liver cirrhosis
  • Infertility and impotence
  • Heart failure
  • Arthritis
  • Diabetes
  • Osteoporosis and joint pain
45
Q

What would happen if beta thalassaemia was left untreated?

A

Person wouldn’t live longer than about 10 years old