hereditary anemia part 1 Flashcards
what are the classifications of hereditary hemolytic anemia?
membrane defects
metabolism defects
haemoglobinopathies
what are some cell membrane defect diseases?
hereditary spherocytosis and elliptocytosis
what is the defect in spherocytosis?
the red blood cells become spherical in shape instead of biconcave so there a decreased surface area , they are unable to pass through the splenic circulation
what is the mode of inheritance of spherocytosis ?
autosomal dominant
what are the clinical features of hereditary spherocytosis
anemia present at any age jaundice is marked if associated with gilberts disease splenomegaly pigment gall stones aplastic crisis
what is the aplastic crisis in spherocytosis usually precipitated by ?
parvo virus
how do we diagnose spherocytosis ?
after full history taking and examination presence of anemia blood film showing microspherocytes increased reticulocytes increased osmotic fragility negative Coombs test
what is coomb test used for ?
to exclude or show any autoimmune haemolysis
what is the principle form of treatment in spherocytosis ?
splenectomy
what are the results after the splenectomy in hereditary spherocytosis ?
anemia improves but micro-spherocytes still form in RE system
hereditary elliptocytosis
similar clinical and lab features as hereditary spherocytosis and is usually discovered by chance
what are some defects in red cell metabolism
G6Pd deficiency
pyruvate kinase deficiency
what are the most common genetic variants of enzyme G6PD
type A (African ) , type B ( western)
what is the mode of inheritance of G6PD ?
sex-linked inheritance (X-linked recessive manner)
what does G6PD protect against ?
has protective measures against malaria
what are the clinical features of G6PD deficiency ?
acute hemolytic anemia
neonatal jaundice
acute hemolytic anemia in G6PD is caused by
intravascular hemolysis
what agents can cause hemolytic anemia in G6PD ?
infections and acute illnesses
Anti malarial drugs, antibacterial agents, analgesics
fava beans
how do we diagnose G6PD?
full history and examination
blood count is normal between crisis
during crisis blood film may show contracted cells , heinz bodies
direct enzyme assay
why may direct enzyme assay give false highs during attack in G6PD ?
assay will show low levels in G6PD when all red cells are of normal age distribution
how do we treat G6PD ?
removal of the offensive/causative agent
maintain a high urine output
blood transfusion may be required in severe anemia
if there is severe neonatal jaundice then phototherapy and exchange transfusion may be required
what is the mode of inheritance in pyruvate deficiency
autosomal recessive
what is the function of pyruvate kinase
production of ATP from glucose
what are the clinical findings in pyruvate deficiency ?
frontal bossing
jaundice is usual
gallstones are frequent
what does the blood ffilm in pyruvate deficiency show ?
poikilocytosis
what is the treatment for pyruvate deficiency ?
splenectomy
how to diagnose pyruvate kinase deficiency ?
direct enzyme assay
what is gilberts syndrome
is a common, harmless liver condition in which the liver doesn’t properly process bilirubin
what is the type of haemolysis in hereditary spherocytosis ?
extravascular haemolysis
