Sickle Cell Disease
Epidemiology
Black population
- heterozygote protective from malaria
- AD
Pathogenesis
Abnormal peptide substitution in ß chain of Hb
- HbS
Homozygous 1%
- HbSS
- sickling occurs with relative hypoxia
- trapped in blood vessels
- necrosis & pain
Heterozygous 8%
- sickle cell trait
- Hb SA