β-thalassaemia
|
Normal
|
αα/αα
|
Normal
|
|
Silent Carrier
|
-α/αα
|
Haematologically silent or mild reduction of MCH/MCV
|
|
Minor
|
-α/-α , - -/αα
|
Borderline anaemia or normal, as well as microcytic and hypochromic red blood cells
|
|
HbH disease*
|
- -/-α , - -/αTα, αTα/αTα
T
- -/- -
T
α
T
α
|
Majority have mild to moderate anaemia and marked microcytosis and hypochromia, only few have phenotype similar to thalassaemia major
|
|
Barts Hydrops Foetalis
|
- -/- -
|
Most develop hydrops foetalis syndrome and die in utero, or shortly after birth
|
β-thalassaemia
|
Normal
|
β/β
|
Normal
|
|
Minor
|
β/β++ , β/β00
|
Borderline anaemia or normal as well as microcytic and hypochromic red blood cells
|
|
β-thalassaemia intermedia*
|
β
+
/β
+
,β
0
/β
+
, β
+
/β, β
0
/β, β
0
/β
0
|
Severity is very variable. Clinical picture ranges from mild to moderate NTDT
|
|
Major
|
β0β0 , β0/β+
|
Severe anaemia requiring regular transfusions (TDT)
|
HbE
|
HbE trait
|
βE/β
|
Asymptomatic condition with no clinical relevance
|
|
Homozygous HbE
|
βE/βE
|
Usually asymptomatic with borderline asymptomatic anaemia and no haemolysis
|
|
HbE/ β-thalassaemia*
|
β
E
/β
+
,β
E
/β
0
|
Severity is very variable. Clinical picture ranges from NTDT to TDT
|
|
HbE/HbS
|
βE/βS
|
Similar to sickle cell disease usually with rare vaso-occlusive crisis
|