congenital anaemias

Question 1

hereditary Spherocytosis

aetio

Answer 1

common - autosomal dominant

Question 2

hereditary Spherocytosis path

Answer 2

defective in cell membranes - structural proteins

causes fragile spherical cells (blood film) - picked up by spleen - excessive haemolysis

Question 3

hereditary Spherocytosis PC

Answer 3

spectrum
mild to severe
picked up early childhood

severe:

• jaundice
• anaemia
• NNU admission
• splenomegaly
• gall stones

Question 4

hereditary Spherocytosis

TX

Answer 4

folic acid supplement due to excessive haemolytic

transfusion

splenomegaly? decrease haemolysis rate

Question 5

RARE hereditary membrane anaemias - recognise -

Answer 5

• Hereditary Elliptocytosis
• Hereditary Pyropoikilocytosis
  South east Asian ovalocytosis

Question 6

G6PD def?

Answer 6

glucose 6 phoshate dehydrogenase deficiency - enzyme/metabolism congenital anaemia

x -linked

Question 7

G6PD def path

Answer 7

G6PD - enzyme that prevents oxidative free radicals destroying Hb - therefore lack of it leads to Hb destruction in RBCs

Question 8

G6PD def blood film?

Answer 8

blister bite cells - oxidative damage to Hb

Question 9

G6PD def common?

Answer 9

commonest enzymopathy in malarial areas (protective)

Question 10

G6PD def PC?

Answer 10

NNU jaundice
pigment gallstones
splenomegaly

Question 11

G6PD def triggers?

Answer 11

• fava beans
• medicines: anti malarial/bacterials
• infections - DKA

Question 12

Sickle cell anaemia form of?

Answer 12

haemoglobinopathy
due to abnormal sickled beta chains -> crystallises + rigid Hb - sickle shape

normal amount of Hb - but defective

Question 13

genetics of Sickle cell anaemia?

Answer 13

autosomal recessive - due to a point mutation

Question 14

Sickle cell anaemia PC?

Answer 14

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

Question 15

management of Sickle cell anaemia ?

Answer 15

lifelong prophylaxis: penicillin + folic acid

acute: supportive, a/bs
blood transfusion

Disease modifying drug: Hydrocarbamid

Question 16

Thalassaemias form of?

Answer 16

congenital anaemia
haemoglobinopathy

reduced or absent globin chain production

Question 17

genetics of Thalassaemias?

Answer 17

autosomal recessive

microcytic anaemia

Question 18

3 forms of Thalassaemias?

Answer 18

1. alpha homozygous Thalassaemia - causes hydrops fetalis
2. Thalassemia minor: heterozygous for one beta chain - minor anaemia - hypochromic microcytic - minor degree of anaemia
3. Thalassaemia major - homozygous def of both beta chains - transfusion dependent

Question 19

management of Thalassaemia major

Answer 19

blood transfusions every 4-6 months - but must CHELATE excess iron -

Question 20

drug used to chelate iron

Answer 20

Oral deferasirox

Question 21

age PC of Thalassaemia major

Answer 21

3-6 months

Question 22

clinical manifestation of Thalassaemia major

Answer 22

head on end skull appearance - proliferation of ineffective bone marrow
splenomegaly
growth retardation

Question 23

curative management of Thalassaemia major

Answer 23

bone marrow transplant

Question 24

life expectancy Thalassaemia major

Answer 24

> 40yo