DR Medhat MRCP

Hb-A (α2β2) Hb-A2 (α2 2) Hb-F (α2 2)
98% of normal adult Hb 1-2 % of normal adult Hb < 1% of normal adult Hb
Its globin is formed of
- 2 α chains + 2 β chains
Its globin is formed of
- 2 α chains + 2 chains
It`s the major type
during fetal life
Its globin is formed of
- 2α chains + 2 chains
• Genetics & inheritance of normal globin molecule :
- The arrangement of the aa of polypeptide chains of globin is encoded by genes :
o 4 genes (2 from each parent) code for synthesis of the 2 α chains ,these genes lie
on chromosome 16.
o 2 genes (1 from each parent) code for synthesis of β-chains , these genes lie on
chromosome 11.
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