Thalassaemia (2) Flashcards
What is it?
What are its 2 types?
How does it affect RBCs?
How is it definitively diagnosed?
➊ Autosomal recessive disorder characterised by defects of Hb’s alpha or beta chains
N.B. Deverity of disease depends on how many of the genes for the globin chains are defective
➋ • a-thalassaemia - Defects in a-chains
• b-thalassaemia - Defects in b-chains
➌ More fragile and easily destroyed
➍ Hb electrophoresis
a-thalassaemia:
What is its pathophysiology?
How does it present?
How is it diagnosed?
How is it managed?
➊ • 2 defective copies (trait) - mildly asymptomatic
• 3 defective copies - symptomatic
• 4 defective copies - incompatible with life
➋ • Jaundice
• Fatigue
• Facial bone deformities
➌ • FBC - shows microcytic anaemia
• Genetic testing
➍ Transfusions and stem cell transplants
• Splenectomy if persistant/recurrent
b-thalassaemia:
What is its pathophysiology?
How does it present?
How is it managed?
What should pts be monitored for when managing?
→ How is this prevented?
➊ Caused by non-functioning copies of the two beta globin genes:
• b-thalassaemia minor (trait) - 1 functional and 1 dysfunctional copy
• b-thalassaemia major (trait) - 2 dysfunctional copies
➋ • b-thalassaemia minor - asymptomatic
• b-thalassaemia major:
‣ Severely symptomatic anaemia at 3-9 months where the normal replacement of HbF with HbA fails
‣ Frontal bossing
‣ Maxillary overgrowth
‣ Hepatosplenomegaly
➌ Regular blood transfusions. The most important long-term consideration in these patients is reducing the risk of iron overload toxicity; a condition which primarily affects the heart, joints, liver and endocrine glands. This can be prevented with iron chelating agents.
➍ Iron overload toxicity
→ Iron chelating agents
