Which of the following is true for sickle cell syndromes?

Sickle cell syndromes are primarily characterized by the presence of abnormal hemoglobin, specifically hemoglobin S (Hb S), which results from a mutation in the beta globin gene. This mutation leads to the typical sickling of red blood cells under conditions of low oxygen, which in turn causes a range of clinical complications.

The correct assertion that it leads to chronic hemolytic anemia is significant because the sickled red blood cells have a shorter lifespan compared to normal erythrocytes—often around 10 to 20 days, compared to the normal lifespan of about 120 days. The chronic destruction of these sickled cells leads to the anemia observed in patients with sickle cell syndromes. This process is compounded by the splenic sequestration of sickled cells and the increased risk of infection, particularly by encapsulated organisms, due to splenic dysfunction.

This chronic hemolysis manifests in symptoms such as fatigue, pallor, and jaundice, as well as complications like vaso-occlusive crises. This is a foundational aspect of the disease, underlining the importance of recognizing chronic hemolytic anemia as a key characteristic of sickle cell syndromes.