Haemogloinopathies Flashcards
What is the structure of HbA?
2 alpha 2 beta
What is the structure of HbA(2)
2 alpha 2 delta
What is the structure of HbF?
2 alpha 2 gamma
Where is the alpha globin-like gene located?
Chromosome 16
Where is the beta globin like gene located?
Chromosome 11
How are haemoglobinopathies generally inherited?
AR
What is a thalassaemia?
Reduced globin chain synthesis leading to inadequate Hb production
Which type of anaemia is seen in the thalassaemias?
Microcytic hypochromic
What is the mildest form of alpha thalassaemia called?
Alpha thal trait
What is HbH disease?
Only 1 functioning copy of the alpha gene
What is Hb Bart Hydrops fetalis?
No functional copies of the alpha gene
How does alpha thal trait present?
Asymptomatic
May have mild anaemia
What is the most severe form of alpha thalassaemia?
Hb Barts Hydrops fetalis
How does HbH disease present?
Splenomegaly Jaundice Severe anaemia Gall stones Growth retardation Iron overload
What happens to excess beta chains in HbH disease?
Form tetramers
How is HbH disease treated?
Transfusions
Maybe splenectomy
Where is HbH disease most common?
SE Asia
Middle east
Which kinds of Hb are found in Hb Barts Hydrops Foetalis?
Hb Barts
HbH
What is Hb Barts?
4 gamma chains
What is HbH
4 beta chains
How does Hb Barts Hydrops Foetalis present?
Severe anaemia
Cardiac failure
Growth retardation
Hepatosplenomegaly
What type of Hb is affected in beta thalassaemia?
HbA
What is the mildest form of beta thalassaemia?
Beta thal trait
How does beta thal trait normally present?
Asymptomatic
Mild anaemia
What does Hb electrophoresis show in beta thal trait?
Increased HbA2 and HbF
How does beta thal intermedia present?
Symptomatic anaemia
May be splenomegaly and iron overload