Etiology:

  • β-globin mutation (Glu→Val) → H • Autosomal recessive

Pathogenesis:

  • Deoxygenated HbS polymerizes → sickling → vaso-occlusion + hemolysis

Clinical Features:

  • Pain crises (vaso-occlusive)

  • Dactylitis (hand-foot swelling in infants)

  • Autosplenectomy → ↑ risk of infection (encapsulated bacteria)

  • Acute chest syndrome, priapism, stroke, leg ulcers

  • Fatigue, jaundice, gallstones

Lab Findings:

  • Normocytic anemia, ↑ reticulocytes

  • Sickled and target cells on smear

  • ↑ Indirect bilirubin, ↑ LDH

  • Hb electrophoresis: ↑ HbS, ↓ HbA

Treatment:

  • Hydroxyurea (↑ HbF)

  • Vaccination, antibiotics, transfusions