Table of contentsWhat is sickle cell disease?Symptoms?Diagnosis?Treatment?What is sickle cell disease? Sickle cell disease, also called sickle cell anemia or simply sickle cell anemia, is a genetic disorder in which red blood cells can take on the shape of a crescent or sickle, and this change allows them to be more easily destroyed, causing anemia among other things. . . Sickle cell disease is caused by a defect in hemoglobin, the protein that carries oxygen in red blood cells. Hemoglobin is actually made up of four peptide chains, each linked to a heme group. Different hemoglobins have different combinations of these chains. Hemoglobin A (or HbA) – composed of two alpha-globin peptide chains and two beta-globin peptide chains – is the main hemoglobin affected in sickle cell disease. Concretely, the beta-globin chains end up deforming, due to a mutation in the beta-globin gene (or HBB gene). Sickle cell disease is an autosomal recessive disorder, so a mutation in both copies of the beta-globin gene is necessary to get the disease. If the person has only one copy of the mutation and a normal HBB gene, then they have sickle cell disease – also called sickle cell trait. Having sickle cell trait does not cause health problems unless the person is exposed to extreme conditions – such as altitude or dehydration – where some symptoms of sickle cell disease may appear. Almost always, the sickle cell mutation is a non-conservative missense mutation, which causes the sixth amino acid in beta globin to be valine instead of glutamic acid. a non-conservative substitution means that the new amino acid – valine, which is hydrophobic – has different properties than the one it replaced – glutamic acid, which is hydrophilic. Say no to plagiarism. Get a tailor-made essay on “Why Violent Video Games Should Not Be Banned”? Get the original essay Symptoms? A hemoglobin tetramer containing two mutated alpha-globin proteins and two beta-globin proteins is called sickle hemoglobin, or HbS. HbS transports oxygen perfectly, but when deoxygenated, HbS changes shape, allowing it to aggregate with other HbS proteins and form long polymers that distort the red blood cell into shape. crescent – ​​a process called sickling. Repeated sickling of red blood cells damages their cell membranes and promotes their premature destruction. Since this occurs in the vascular system, it is called intravascular hemolysis. This destruction of red blood cells not only leads to anemia, i.e. a deficiency of red blood cells, but also causes a significant loss of hemoglobin. Recycling of this heme group produces unconjugated bilirubin which, at high concentration, can cause scleral jaundice, jaundice, and bilirubin gallstones. To combat anemia due to sickle cell disease, the bone marrow produces increased numbers of reticulocytes, which are immature red blood cells. This eventually causes new bone formation and the marrow cavities of the skull can expand outward, causing enlargement of the cheeks and a “spiky hair” appearance on the skull x-ray. Extramedullary hematopoiesis – which is the production of red blood cells outside of the bone marrow – can also occur, most commonly in the liver, which can cause hepatomegaly. Sickle-shaped, red blood cells tend to get stuck in the capillaries, which is called vaso-occlusion. From early childhood, they can obstruct blood flow to the bones of the hands and feet. More,.