Etiology:
Autosomal recessive disorder caused by a mutation in the β-globin gene (HBB) on chromosome 11
HbS formation instead of normal HbA
Triggered by hypoxia, dehydration, acidosis
- Pathogenesis:
HbS polymerizes under low oxygen → RBC sickling
Sickled cells are rigid → vaso-occlusion → ischemia & infarction
Hemolysis leads to anemia, jaundice, and increased bilirubin
- Clinical Features:
Painful vaso-occlusive crisis (hands, feet, chest, abdomen)
Hemolytic anemia (jaundice, pallor, fatigue)
Dactylitis (painful swelling of hands/feet in children)
Splenic sequestration crisis → sudden anemia, hypovolemia
Acute chest syndrome (life-threatening pulmonary complication)
Increased risk of infections (due to functional asplenia)
- Treatment:
Hydroxyurea (increases HbF production, reduces sickling)
Folic acid supplementation (supports RBC production)
Pain management (NSAIDs, opioids for severe pain)
Blood transfusions (for severe crises)
Bone marrow transplantation (curative but rarely done)a