Hi, need to submit a 2000 words paper on the topic Sickle-Cell Anemia. Sickle-cell anemia is common in population in Saharan Africa and their descendants from parts of the world. Sickle-cell disease can occur in any individual of any race or ethnicity across the globe.”Sickle-cell anemia” is a specific form of sickle-cell disease caused by a homozygous mutation forming Hgb S. Other forms of the sickle-cell disease include sickle-hemoglobin C disease, sickle beta-plus-thalassemia, sickle beta-zero-thalassemia and hemoglobin ss caused by heterozygous genes (Orah, 2000). The origin of the mutation that led to the sickle cell gene was initially thought to be in the Arabian region spreading to Asia and Africa. It is now confirmed from an evaluation of chromosome structures that there should have been at least four independent mutational events spanning over 70000 to 150000 years, three in Africa and a fourth in either Saudi Arabia or central India. The evolution of sickle-cell anemia is understood and explained as an example of Baldwinian phylogeny whereby humans modify their environment and thus change the selective pressures.Patients with sickle cell anemia exhibit anemia with typical hemoglobin levels of 6-9 g/dl. Evaluation of reticulocytes reflects new red blood cells replacing the rapidly destroyed older cells because of a drastic reduction in red blood cell life span. Reticulocytes are immature red blood cells, typically comprising about 1% of the red cells in the human body. Reticulocytes develop and mature in the bone marrow and then circulate for about a day in the bloodstream before developing into mature red blood cells. Reticulocytes do not have a nucleus. They are called reticulocytes because of a reticular or mesh-like network of ribosomal RNA. Reticulocytes appear slightly bluer than other red cells when looked at with the normal Romanowsky staining procedure. Evaluation of the white blood cell and platelet counts indicate vaso-occlusion( Kinney et al.1999).Complications of Sickle cell AnemiaVaso-occlusive crisesMost patients with sickle cell disease suffer intensely painful episodes called vaso-occlusive crises The frequency, severity, and duration of these crises vary tremendously. Such painful crises are treated with hydration and analgesics. A vaso-occlusive crisis is a condition caused by sickle-shaped red blood cells that obstruct capillaries and restrict blood flow to an organ often resulting in pain, ischemia and organ damage. The Spleen is frequently affected due to narrow blood vessels and its metabolic function in clearing defective red blood cells. It is usually in the infracted state before even the end of childhood in sickle-cell anemia cases (Orah, 2000). .