Trait is common with a hypochromic microcytic anaemia with target cellls and increased HbA2 on electrophoresis
- Inherited defect causing reduced production of beta-globin
- Fetal Hb has no Beta globin chains so there is no disease until HbF levels drop after birth.
- Defect in all Beta globin genes leads to Thalassaemia major
- Increase in HbA2 with 2 a and 2 d globin chains.
- There is an imbalance in globin chains
- Asian, Arabic or Mediterranean origin
- In adults the Hb is composed of 2 a chains and 2 ß chains.
- In Beta Thalassaemia there is a defect in making Beta chains
- There are 2 genes per cell producing Beta chains
- Many gene mutations leading to variable Beta chain production
- There is haemolysis and ineffective erythropoiesis
- Thalassaemia major - severe requires transfusions lifelong. Iron overload.
- Thalassaemia intermedia - lifelong anaemia but fewer transfusion needs
- Thalassaemia minor - asymptomatic carrier
- Extramedullary haemopoiesis leads to an expansion of bone marrow and hepatosplenomegaly. Skull marrow expansion leads to deformity which is often in the exams shown as a skull x-ray "hair on end appearance". Osteopenia.
- Organ damage from Iron overload causes endocrine disease with pituitary,
hypothyroidism and diabetes mellitus and hypogonadism as well as cardiac
damage. Leg ulcers, gallstones, an aplastic crisis with intermedia
- Those with Beta thalassaemia trait may have problems during haemopoietic
stress such as pregnancy and show mild anaemia and microcytosis
- Microcytic hypochromic anaemia and target cells.. The MCV is much lower than would be expected.
- Raised reticulocyte count
- Raised HbA2, HbF and absent HbA ( a2d2 Hb on
- Ferritin high with repeated transfusions
- Transfusion to 9 to 10 g/dL- leads to Iron overload needing regular
chelation therapy with desferrioxamine
- Splenectomy may reduce transfusion need
- Oral Folate is needed
- Large doses of Vitamin C helps excrete iron
- Haematopoietic cell transplantation for severe