Table 99-2 Clinical Features of Sickle Hemoglobinopathies

Condition	Clinical Abnormalities	Hemoglobin Level g/L (g/dL)	MCV, fL	Hemoglobin Electrophoresis
Sickle cell trait	None; rare painless hematuria	Normal	Normal	Hb S/A:40/60
Sickle cell anemia	Vasoocclusive crises with infarction of spleen, brain, marrow, kidney, lung; aseptic necrosis of bone; gallstones; priapism; ankle ulcers	70–100 (7–10)	80–100	Hb S/A:100/0 Hb F:2–25%
S/beta° thalassemia	Vasoocclusive crises; aseptic necrosis of bone	70–100 (7–10)	60–80	Hb S/A:100/0 Hb F:1–10%
S/beta+ thalassemia	Rare crises and aseptic necrosis	100–140 (10–14)	70–80	Hb S/A:60/40
Hemoglobin SC	Rare crises and aseptic necrosis; painless hematuria	100–140 (10–14)	80–100	Hb S/A:50/0 Hb C:50%