Thalassaemia Flashcards
thalassaemia
name for a group of inherited conditions that affects a substance in the blood called haemoglobin
people with thalassaemia produce either…
no or too little haemoglobin
thalassaemia can be divided into…
alpha & beta
most severe type of thalassaemia
beta thalassaemia major
alpha thalassaemia
normal
- all alpha globin chains present
alpha thalassaemia
carrier
- one missing gene
- silent carrier
- no abnormalities
alpha thalassaemia
Alpha thalassaemia minor
- two missing genes
- asymptomatic
- mild microcytic anaemia
alpha thalassaemia
HbH disease
- three missing genes
- symptomatic
- mild to severe anaemia
- splenomegaly
alpha thalassaemia
alpha thalassaemia major
- all 4 missing genes
- incompatible with life
alpha thalassaemia results from deletions involving what genes?
HBA1 + HBA2
alpha thalassaemia presentation
malformed red blood cells
reduce oxygen carrying
* pallor
* shortness of breath
* fatigue
body removes damaged red cells
* enlarged spleen
* low number of cells
* jaundice
alpha thalassaemia treatment for anaemia
- folic acid + good nutrition
- transfusions of packed red cells
alpha thalassaemia treatment long term
- bone marrow transplant
- splenectomy
alpha thalassaemia treatment
avoid passing on condition
genetic counselling
what is beta thalassaemia
range of inherited conditons affecting B chains in haemoglobin
what is beta thalassaemia caused by?
caused by point mutations to a single gene on chromosome 11
beta thalassaemia inherited in an…
autosomal recessive fashion
beta thalassaemia
normal
healthy (B/B)
beta thalassaemia minor
- B/B+
- B/B0
- mild anaemia
beta thalassaemia intermedia
- B+/B0
- may need transfusions
beta thalassaemia major
- B+/B+
- B0/B0
- both alleles have mutation
- severe anaemia
- bone deformities
why does beta thalassaemia cause bone deformities?
- makes bone marrow expand
- bones widen
- results in abnormal bone structure ( esp face + skull )
- also makes bones thin and brittle
- increasing chance of broken bones
