Is an inherited blood disorder that affects red blood cells. People with sickle cell disease have red blood cells that contain mostly hemoglobin S, an abnormal type of hemoglobin. Sometimes these red blood cells become sickle-shaped (crescent shaped) and have difficulty passing through small blood vessels.
Sickle cell disease is a chronic hemolytic anemia occurring almost exclusively in those of African American descent, characterized by sickle-shaped red blood cells (RBCs) due to homozygous inheritance of hemoglobin S (HbS). In HbS, valine is substituted for glutamic acid in the sixth amino acid of the β-chain. Due to this molecular change, this form of hemoglobin is less soluble and can form rodlike tactoids that cause red blood cells to sickle at sites of low oxygen pressure. Distorted, inflexible RBCs plug small arterioles and capillaries, which leads to occlusion and infarction. Because sickled RBCs are too fragile to withstand the mechanical trauma of circulation, hemolysis occurs after they enter the circulation.
A hereditary blood disease that affects blacks. It is characterized by the production of an abnormal type of ‘hemoglobin, sickle-cell hemoglobin (Hbs), in the red blood cells. Hbs becomes insoluble when the blood is deprived of oxygen and precipitates, forming elongated crystals that distort the blood cell into the characteristic sickle shape: this process is known as sickling. Sickle cells are rapidly removed from the circulation, leading to anemia. There is no satisfactory treatment, but patients with this disease are resistant to infection with Plasmodium falciparum, which causes a serious form of malaria.
Sickle cell anemia is an inherited disorder characterized by the presence of an abnormal variant of hemoglobin, a vital protein responsible for carrying oxygen within red blood cells. This abnormal form of hemoglobin leads to the deformation of red blood cells, causing them to acquire a sickle- or crescent-shaped structure. These distorted cells have the potential to obstruct blood vessels, hindering the proper delivery of oxygen to tissues. Consequently, individuals with sickle cell anemia may experience pain, blood clot formation, and various other complications. This condition is most prevalent among individuals of African descent and those with ancestral ties to Italy, Greece, India, and the Middle East.