Hemoglobin failure, or abnormal hemoglobin (such as that of sickle-cell disease). The ability of each hemoglobin molecule to carry oxygen is normally modified by altered blood pH or CO, causing an altered oxygen–hemoglobin dissociation curve. However, it can also be pathologically altered in, e.g., carbon monoxide poisoning. Decrease of hemoglobin, with or without an absolute decrease of red blood cells, leads to symptoms of anemia. Anemia has many different causes, although iron deficiency and its resultant iron deficiency anemia are the most common causes in the Western world. As absence of iron decreases heme synthesis, red blood cells in iron deficiency
Hemoglobin C cell crises. The peripheral smear demonstrates mostly target cells and only a few sickle cells. However, persons with hemoglobin SC disease (HbSC) have more significant retinopathy, ischemic necrosis of bone, and priapism than those with pure SS disease. People with hemoglobin C trait, or hemoglobin C carriers, have one gene for HbC and one normal gene. Their red blood cells contain both normal hemoglobin A and also hemoglobin C. People with hemoglobin C trait have slightly more hemoglobin A than hemoglobin C in their cells. Hemoglobin C disease is an autosomal recessive disorder that results from the biparental inheritance of