Haemoglobulinopathies Flashcards
Alpha like genes are on which chromosome?
16
Beta like genes are on which chromosome?
11
When are adult levels of Hb reached?
by 6-12 months of age
What are the two main haemoglobulinopathies?
Thalassaemias
Structural haemoglobin variants;
Which type of haemoglobulinopathy decreases rate of globin chain production?
thalassaemias
In which type of haemoglobulinopathy is there normal production of structurally abnormal globin chain, leading to a variant type of haemoglobin?
Structural haemoglobin variants
What are the commonest monogenic disorders?
thalassaemias
How many genes are affected in silent a thal trait?
1 gene
How many genes are affected in α thal trait?
2
How many genes are affected in HbH disease?
3
How many genes are affected in Hb Barts hydrops fetalis?
4
What type of red cells are there in alpha thal trait?
Microcytic, hypochromic red cells with mild anaemia
In alpha thal trait, what can sometimes be seen on special stain?
red cell inclusions
Why does splenomegaly occur in HbH disease?
due to extramedullary haematopoiesis
What is Hb Bart’s Hydrops Fetalis Syndrome?
Severest form of α thalassaemia
Occurs when no α genes inherited from either parent
Most die in utero
What inheritance occurs in beta thal trait?
autosomal recessive
Describe the 3 types of beta thal?
β thalassaemia trait Asymptomatic Low MCV/MCH Raised HbA2 is diagnostic β thalassaemia intermedia Moderate severity requiring occasional transfusion β thalassaemia major; Severe, lifelong transfusion dependency
What inheritance occurs in sickle cell anaemia?
autosomal recessive
Sickle cell vaso-occlusion occurs causing what?
Consequences; tissue ischaemia and severe pain
Treatment of painful crisis in sickle cell?
Opiate analgesia Hydration, Rest Oxygen Antibiotics if evidence of infection Red cell exchange transfusion in severe crises eg chest crisis or neurological symptoms
What can reduce severity of disease by inducing HbF production?
Hydroxycarbamide
