Sickle cells (Drepanocytes)

Definition:

Sickle cells are half-moon-shaped (sickle-shaped) erythrocytes. They result from the polymerization of hemoglobin S. Polymerization is induced by decreased oxygen tension and/or acidosis.

Occurrence:
Sickle cell anemia: This inborn defect of hemoglobin synthesis (beta chain defect) is very widespread in Africans due to its association with protection from malaria.