Haem - Thalassaemia Flashcards
What is thalassaemia?
Genetic defect in protein chains that make up Hb
What protein chains is normal Hb made of?
2 alpha and 2 beta globin chains
What is an alpha vs beta thalassaemia?
Alpha - defect in alpha globin chains
Beta - defect in beta globin chains
Both are autosomal recessive conditions
What happens to RBCs in patients with thalassaemia?
More fragile and break down more easily
Why do patients with thalassaemia get splenomegaly?
Spleen collects all the destroyed RBCs
How is chronic anaemia due to thalassaemia compensated for?
Bone marrow expands to produce extra RBCs
What does bone marrow expansion lead to?
Increased susceptibility to fractures
Pronounced forehead
Pronounced malar eminences
What are the potential signs of thalassaemia?
Microcytic anaemia
Pallor
Jaundice
Gallstones
Splenomegaly
Poor growth and development
Pronounced forehead and malar eminences
Fatigue
How is thalassaemia diagnosed?
- FBC - shows microcytic anaemia
- Haemoglobin electrophoresis - diagnose globin abnormalities
- DNA testing - genetic abnormality
Pregnant women offered screening test for thalassaemia at booking
Why does iron overload occur in thalassaemia?
- Faulty RBC synthesis
- Recurrent transfusions
- Increased iron absorption in gut in response to anaemia
How are patients with thalassaemia monitored?
Serum ferritin levels to check for iron overload
How is iron overload managed?
Limit transfusions
Iron chelation
What does iron overload cause?
Fatigue
Liver cirrhosis
Infertility
Impotence
Heart failure
Arthritis
Diabetes
Osteoporosis and joint pain
What is alpha-thalassaemia caused by?
Autosomal recessive gene mutation on chromosome 16 which codes for alpha globin chains
How is alpha thalassaemia managed?
- Monitor FBC
- Monitor complications
- Blood transfusions
- Splenectomy
- Bone marrow transplant - may be curative