Sickle Cell Anemia: Inherited Disorder of Red Blood Cell Shape

Sickle cell anemia is an autosomal recessive hemoglobinopathy (HbSS) where a single amino acid substitution (valine for glutamic acid at β-globin position 6) causes hemoglobin to polymerize when deoxygenated.

Pathophysiology

• RBCs sickle → rigid, sticky, short-lived (10–20 days vs. 120).
• Hemolysis → anemia, jaundice, gallstones.
• Vaso-occlusion → ischemic pain crises, organ infarction (spleen, brain, kidneys, bones).

Key Features

• Chronic hemolytic anemia
• Recurrent acute pain crises
• Functional asplenia → infection risk (encapsulated bacteria)
• Stroke, acute chest syndrome, priapism, leg ulcers

Management

• Hydroxyurea (increases HbF, reduces crises)
• Penicillin prophylaxis (children), vaccinations
• Transfusion for stroke prevention/treatment
• Curative: allogeneic stem cell transplant; gene therapy emerging.

Newborn screening enables early intervention. Multidisciplinary care improves survival and quality of life.