Haemoglobinopathies - thalessaemia Flashcards
What is thalassaemia?
a group of inherited disorders of Hb synthesis
reduced or absent globin chain production
mutation or deletion haemoglobin genes
what is alpha thalassaemia?
mutation or deletion in alpha genes
What does the chain imbalance in e.g. alpha thalassaemia cause?
alpha chain cant bind to the beta chain
- chains going about and nothing to bind to
chronic haemolysis
ineffective erythropoiesis
anaemia
Inheritance of thalassaemia?
autosomal recessive
you get carriers
How to identify thalassaemia carriers?
they have hypochromic microcytic red cells (small pale cells)
otherwise well and asymptomatic
can be confused with iron deficiency
What can carriers of thalassaemia be confused with?
iron deficiency
due to hypochromic microcytic RBC
How to differentiate thalassemia and iron deficiency?
no reason for pt to be iron deficient: good diet etc
check ferratin
What do you call homozygous thalassaemia of alpha chian?
you lose all of your alpha chains
= homozygous alpha zero thalassaemia
incompatible with life - as the beta, delta, gamma cant bind with anaything
Can you survive with homozygous beta thalassaemia?
yes, you can make gamma-alpha haemoglobin (foetal)
you can make alpha-delta haemoglobin
transfusion dependent
What is homozygous beta thalassaemia called?
beta thalassaemia major
its a severe anaemia
When is beta thalassaemia major symptoms occur?
present at 3-6 months age
when the adult beta-alpha chains try to form
What occurs if beta thalassemia major is untreated or under transfused?
expansion of ineffective bone marrow
bony deformities
- dental malocclusion
splenomegaly
- children show with swollen bellies
growth retardation
- huge metabolic demand to make haemoglobin and not manage to grow
osteoporosis
- bone marrow expanded
With no tx at all, what is the expected life expectancy?
under 10 years
disease?
beta thalassaemia major
Tx for beta thalassemia major?
CHRONIC TRANSFUSION SUPPORT 4-6 WEEKLY
consequence iron overload
