Sickle-Cell Anaemia Introduction
Introduction:
Sickle-cell anaemia (SCA) also called Sickle-cell disease (SCD), is a genetic blood disorder. It occurs due to a mutation in the haemoglobin gene. In sickle-cell anaemia, red blood cells become rigid, less flexible and adopt sickle shape. Sickle-cell disease occurs more commonly among people whose ancestors lived in tropical and sub-tropical sub-saharan regions. In Sickle cell disease, human blood contains both normal red blood cells and sickle-shaped cells. Sickle-cell disease causes various acute and chronic complicatioans, that leads to mortility.
Anemia and various crises including the vaso-occlusive crisis, aplastic crisis, sequestration crisis, haemolytic crisis and others are the results of Sickle-cell disease. Many episodes of sickle cell crises last between five and seven days. Sickle-cell anaemia is caused by a point mutation in which the hydrophilic amino acid glutamic acid is replaced with the hydrophobic amino acid valine at the sixth …show more content…
position in the β-globin chain of haemoglobin on chromosome 11. The two mutant beta-globin subunits forms haemoglobin S (HbS). Under low-oxygen, the presense of non-polar amino acid at position six of the beta-globin chain promotes the non-covalent polymerisation of haemoglobin, causes the red blood cells to change into sickle shaped, which results in decrease in their elasticity. Under normal oxygen, sickled shaped cells fail to return to their normal shape. The loss of red blood cells elasticity is integral to sicklecell disease. Normal red blood cells are quite elastic, they deform and pass through capillaries with no trouble.
Sickle cells are rigid, unable to deform and pass through narrow capillaries with great troubles. This leads to vessel occlusion and ischaemia. Because of misshape of sickle cells, they undergo hemolysis and destroy, causing Anemia. Healthy red blood cells normally survive 90-120 days, but sickle cells only survive 10-20 days. Although the bone marrow, creates new red cells, but the rate of production is quite less the rate of destruction.
Mostly the patients with sickle cell anaemia are somehow in good health. They achieve a steady state level of fitness in which infections,acute complicating factors or acute clinical crisis are absent for at least threee months. Sickel Cell Anaemia a foremost root of morbidity and mortality in Africa and extensively spread in regions of Sicily and southern Italy, northern Greece, southern Turkey, the Middle East, Saudi Arabia, much of central India, and the
Americas.
Sickle-cell anaemia (SCA) also called Sickle-cell disease (SCD), is a genetic blood disorder. It occurs due to a mutation in the haemoglobin gene. In sickle-cell anaemia, red blood cells become rigid, less flexible and adopt sickle shape. Sickle-cell disease occurs more commonly among people whose ancestors lived in tropical and sub-tropical sub-saharan regions. In Sickle cell disease, human blood contains both normal red blood cells and sickle-shaped cells. Sickle-cell disease causes various acute and chronic complicatioans, that leads to mortility.
Anemia and various crises including the vaso-occlusive crisis, aplastic crisis, sequestration crisis, haemolytic crisis and others are the results of Sickle-cell disease. Many episodes of sickle cell crises last between five and seven days. Sickle-cell anaemia is caused by a point mutation in which the hydrophilic amino acid glutamic acid is replaced with the hydrophobic amino acid valine at the sixth …show more content…
position in the β-globin chain of haemoglobin on chromosome 11. The two mutant beta-globin subunits forms haemoglobin S (HbS). Under low-oxygen, the presense of non-polar amino acid at position six of the beta-globin chain promotes the non-covalent polymerisation of haemoglobin, causes the red blood cells to change into sickle shaped, which results in decrease in their elasticity. Under normal oxygen, sickled shaped cells fail to return to their normal shape. The loss of red blood cells elasticity is integral to sicklecell disease. Normal red blood cells are quite elastic, they deform and pass through capillaries with no trouble.
Sickle cells are rigid, unable to deform and pass through narrow capillaries with great troubles. This leads to vessel occlusion and ischaemia. Because of misshape of sickle cells, they undergo hemolysis and destroy, causing Anemia. Healthy red blood cells normally survive 90-120 days, but sickle cells only survive 10-20 days. Although the bone marrow, creates new red cells, but the rate of production is quite less the rate of destruction.
Mostly the patients with sickle cell anaemia are somehow in good health. They achieve a steady state level of fitness in which infections,acute complicating factors or acute clinical crisis are absent for at least threee months. Sickel Cell Anaemia a foremost root of morbidity and mortality in Africa and extensively spread in regions of Sicily and southern Italy, northern Greece, southern Turkey, the Middle East, Saudi Arabia, much of central India, and the
Americas.