DR Medhat MRCP

Hemoglobinopathies
Quantitative
(Imbalanced numbers of globin chains synthesis)
Qualitative
(Structural Hb abnormality)
Thalassemia.
Methemoglobinemia
1) Sickle cell disease
2) Methemoglobinemia
3) Others.
- It describes presence of inactive form of iron (ferric Fe +3 ) in Hb instead of normal
active (ferrus F +2 ) form in the blood.
- This is normally regulated by NADH methemoglobin reductase, Hb-M ,Hb-H which
transfers electrons from NADH to methemoglobin resulting in the reduction of
methemoglobin to hemoglobin
if reductase ,Hb-M ,Hb-H abnormality, There is
tissue hypoxia as Fe3+ cannot bind oxygen, and hence the oxidation dissociation
curve is moved to the left.
Methemoglobinemia = oxidation of Fe2+ in hemoglobin to Fe3+
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