thalassemia Flashcards
what is thalassemia characterised by
smaller than normal red blood cells. - (all microcytic anaemias have this)
It’s a genetic haemoglobinopathy which results in fragile RBCs.
what causes thalassemia
is an autosomal recessive disorder
that is due to defective haemoglobin chains
where is thalassemia more prevalent
in countries with malaria
because it provides resistance against the disease.
pathophyisology of thalassemia
- Either the alpha- or beta-globin chain is affected (alpha or beta thalassaemia).
- Whichever chain is affected, there is an imbalance between the amount of the 2 types of chain, leading to fragile RBCs.
- The spleen collects all the broken RBCs which can result in splenomegaly.
- To compensate, the bone marrow expands to produce more RBCs
- leading to fractures, bone deformities, pronounced foreheads, and molar eminences.
at what age is thalassemia usually diagnosed at
young children
which type of thalassemia is more common - alpha or beta
beta
what is alpha thalassemia a result of
due to 4 gene deletions on chromosome 16.
It is associated with HbH and can cause death in utero if severe.
what is beta thalassemia a result of
a result of 2 gene mutations on chromosome 11.
Hb isoforms are normal, the beta chains are just deplete
symptoms of thalassemia
- Shortness of breath
- Palpitations
- Fatigue
- Swollen abdomen
- Growth restriction
signs of thalassemia
- Jaundice
- Pallor
- Hepatosplenomegaly
- Chipmunk face: enlarged
forehead and cheekbones - Failure to thrive
- Bone deformities
3 investigations for thalassemia
- FBC + blood film
- haemoglobin electrophoresis (diagnostic)
- skull x ray
what does FBC + Blood film of thalassemia show
- Microcytic
- low MCV
- hypochromic RBCs
- Target cells
- high reticulocytes
- high ferritin
what does skull x ray of thalassemia show
will show “hair on end” appearance of the skull.
4 treatment options for thalassemia
- regular blood transfusions - with iron chelation
- ascorbic acid
- splenectomy
- bone marrow transplant - curative
