congenital anaemias Flashcards
hereditary Spherocytosis
aetio
common - autosomal dominant
hereditary Spherocytosis path
defective in cell membranes - structural proteins
causes fragile spherical cells (blood film) - picked up by spleen - excessive haemolysis
hereditary Spherocytosis PC
spectrum
mild to severe
picked up early childhood
severe:
- jaundice
- anaemia
- NNU admission
- splenomegaly
- gall stones
hereditary Spherocytosis
TX
folic acid supplement due to excessive haemolytic
transfusion
splenomegaly? decrease haemolysis rate
RARE hereditary membrane anaemias - recognise -
- Hereditary Elliptocytosis
- Hereditary Pyropoikilocytosis
South east Asian ovalocytosis
G6PD def?
glucose 6 phoshate dehydrogenase deficiency - enzyme/metabolism congenital anaemia
x -linked
G6PD def path
G6PD - enzyme that prevents oxidative free radicals destroying Hb - therefore lack of it leads to Hb destruction in RBCs
G6PD def blood film?
blister bite cells - oxidative damage to Hb
G6PD def common?
commonest enzymopathy in malarial areas (protective)
G6PD def PC?
NNU jaundice
pigment gallstones
splenomegaly
G6PD def triggers?
- fava beans
- medicines: anti malarial/bacterials
- infections - DKA
Sickle cell anaemia form of?
haemoglobinopathy
due to abnormal sickled beta chains -> crystallises + rigid Hb - sickle shape
normal amount of Hb - but defective
genetics of Sickle cell anaemia?
autosomal recessive - due to a point mutation
Sickle cell anaemia PC?
vaso occlusive tissue disease leads to:
- trapping in bones: bony pain
- trapping in spleen: childhood - infarcts + pooling of blood –> hyposplenism in adult hood (prone to infections)
- strokes or PE
- excess haemolysis = gallstones
management of Sickle cell anaemia ?
lifelong prophylaxis: penicillin + folic acid
acute: supportive, a/bs
blood transfusion
Disease modifying drug: Hydrocarbamid
Thalassaemias form of?
congenital anaemia
haemoglobinopathy
reduced or absent globin chain production
genetics of Thalassaemias?
autosomal recessive
microcytic anaemia
3 forms of Thalassaemias?
- alpha homozygous Thalassaemia - causes hydrops fetalis
- Thalassemia minor: heterozygous for one beta chain - minor anaemia - hypochromic microcytic - minor degree of anaemia
- Thalassaemia major - homozygous def of both beta chains - transfusion dependent
management of Thalassaemia major
blood transfusions every 4-6 months - but must CHELATE excess iron -
drug used to chelate iron
Oral deferasirox
age PC of Thalassaemia major
3-6 months
clinical manifestation of Thalassaemia major
head on end skull appearance - proliferation of ineffective bone marrow
splenomegaly
growth retardation
curative management of Thalassaemia major
bone marrow transplant
life expectancy Thalassaemia major
> 40yo
