Thalassemia

Question 1

What is alpha thalassemia?

Answer 1

Alpha thalassemia affecting 4 loci can cause Hb Bart’s and hydrous fetalis
-> more present in Africa, Southeast Asia

Question 2

What is thalassemia?

Answer 2

Thalamseemia is a defect in the globin chain of haemoglobin, split into alpha and beta thalassemia. These are insoluble and rpecipate in the RBCs, causing the spleen to initiate haemolysis and leading to ineffective erythropoeisis.

Question 3

What is beta thalassemia?

Answer 3

Beta thalassemia results from point nonsense mutations and can be heterozygous and cause minor Microcytic anaemia. There is risk of precipitating of RBCs and inducing haemolysis, eventually leading to jaundice and hepatosplenomegaly

Question 4

What is the Mentzer index?

Answer 4

It is used to differentiate between iron deficiency anaemia and thalassemia based on MCV/RBC.

In thalassemia, Mentzer index is always over 13.

Question 5

What are the blood film findings for alpha thalassemia?

Answer 5

In alpha thalassemia, Mentzer index is 13 and may have tear drop cells, target cells

Question 6

What are the blood film findings for beta thalassemia?

Answer 6

In beta thalassemia major, there will be Howell jolly bodies, high reticuloycyte count, tear drop and target cells and high levels of unconjugated hyperbilirubinaemia

Question 7

Which demographic is affected by alpha thalassemia major?

Answer 7

Foetus with hydrous foetal is

Question 9

When does thalassaemia typically present?

Answer 9

In babies due to maintained production of HbF and Extramedullary haematopoesis causes frontal bossing
-> Middle Eastern or Far Eastern are more at risk

Question 10

Which condition is at increased risk in thalassemia?

Answer 10

Secondary haemochromatosis due to excess blood transfusing
-> treat with desferrioxamine