Sickle Cell Anaemia Flashcards
Aetiology sickle cell?
Autosomal recessive mutation of HbA
HBB gene
What type of mutation is sickle cell?
Missense
What does the missense HbA mutation lead to?
Misshapen B-globin chain
Pathology of sickle cell?
Misshapen b globin can carry oxygen but sickles when deoxygenated
Polymerates with other sickles
What does the sickle polymerisation lead to?
Intrinsic extravascular haemolysis
Vaso-occlusion
What can vaso-occlusion cause in sickle cell?
- Stroke
- Pain
- Acute chest syndrome
What is acute chest syndrome?
Pulmonary hypertension
Typical presentation?
” 6 month old black baby presents with 2 day history of fever and painful hands that are swollen. He has been totally hysterical for 6 hours and has not been feeding as much. “
Symptoms?
Vaso-occlusion
- Pain and swelling of hands
Pain
- Bone pain from expansion
Dactylitis
Chronic haemolysis
What can chronic haemolysis lead to?
Pigment gallstones
Investigations?
Newborn blood spot screening
Bloods
CT head
CxR
What bloods are done?
FBC
Reticulocyte count
Blood film
Haptoglobin levels
What is seen on blood smear?
Howell jolly bodies
When is a CT head implicated?
Stroke
Moya moya disease
When is a CxR implicated?
Acute chest syndrome