Thalassaemia Flashcards
What is thalassaemia?
Genetic unbalanced Hb synthesis with underproduction or no production of one globin chain
This causes damage to RBC membranes causing haemolysis
What is beta thalassaemia major?
Absece of beta chains
Chromosome 11
How does beta thalassaemia major present?
Presents in 1st year Severe anaemia (microcytic) Failure to thrive Extra medullary haematopoiesis causes characteristic head shape - skull bossing Hepatosplenomegaly
HbA2 and HbF raised
HbA absent
What is management of beta thalassaemia major
Life long blood transfusions required
This results in iron overload/deposition seen after 10 years as endocrine failure (pituitary, thyroid, pancreas -> DM)
Aim for Hb > 90 to suppress ineffective extramedullary haematopoiesis
Splenectomy if hypersplenism persists with increasing transfusion requirements
(avoid til >5 years due to infection risk
Hormone replaceemnt for endocrine complications
What does iron overload cause? How is it treated?
Hypothyroidism
Hypocalcaemia
Hypogonadism
Desferroxamine SC infusion twice weekly
(Iron chelator)
What is beta thalassaemia trait?
Reduced beta chain production Carrier state
Usually asymptomatic
Mild hypochromic, microcytic anaemia
HbA2 raised
What is prevention of beta thalassaemia?
Genetic counseeling
Antenatal diagnosis using fetal blood or DNA
What Ix?
FBC MCV Film Iron HbA2 HbF Hb electrophoresis
What is alpha thalassamia? Features of haemolysis?
Mainly caused by genetic deletions for allpha genes on chromosome 16
Bart’s hydrops - all four alpha genes deleted - in utero death
HbH if 3 alpha genes deleted Anaemia and features of haemoalysis: Hepatosplenomegaly Leg ulcers Jaundice
What is seen on blood film in alpha thalassaemia?
Microcytic cells
Target cells
Howell Jolly body