Sickle Cell Anemia

¶ … relationship among African-Americans, Malaria and Sickle cell anemia. Many people born in regions affected by malaria are resistant to the disease. Malaria, rampant in parts of Africa, south of the Sahara has killed millions of people many of them little children. Further examination shows that those who are resistant to the disease carry at least one sickle cell trait. Blacks in America whose ancestors hail from Africa show a higher incidence of the disease.

Are African-Americans who carry the abnormal gene proof of a genre of natural selection, allowing those with the trait to survive and those without the trait to perish? I will explore the link between those with the sickle cell gene and their apparent immunity from malaria and the connection between African-Americans and their ancestors. What is Sickle Cell Anemia? Linus Pauling originally discovered sickle cell in 1949. Sickle cell anemia is a red blood cell disorder that can be passed down from generation.

Sickle cell anemia is so named because the red blood cells in the infected person resemble a sickle that is used to cut wheat; infected cells also become sticky and hard. A person who does not have the disease has blood cells that resemble a doughnut in shape. See picture below. On the left illustrates normal blood cells. The picture on the right shows the blood cells of a person with sickle cell anemia.

Courtesy of the University of Michigan Normal Red Blood Cells Sickle Red Blood Cells Sickle cell is caused by changes in the hemoglobin, which is a substance found inside the red blood cell its main function is to carry oxygen inside the cell. A tiny modification of this substance causes long rods to form in the cell when it is omitting oxygen, thereby giving the cell its sickle shape.

Who Is Affected By Sickle Cell Anemia? Sickle cell is inherited disease children acquire the disease from parents who may have the disease or carry the trait. Sickle cell anemia is not contagious. Sickle cell is most prevalent in African-Americans, Greeks, Latin Americans, Italians, Indians and Arabs. However, there have been recorded cases of other groups such as whites having the disease. No one is immune, and everyone should be tested. Common Genre of Sickle Cell Anemia The top three most common types of Sickle cell in America are: 1.

Hemoglobin SS or sickle cell anemia 2. Hemoglobin SC disease 3. Hemoglobin sickle beta-thalassemia While there are some fundamental differences among the three types of Sickle cell, there is not one that is less painful than the other. No matter what type of Sickle cell anemia a person suffers from everyone affected can experience some devastating complications. Common complications experienced by Sickle cell patients are: leg ulcers, kidney damage, strokes, bone damage increased infections and delayed growth.

In order to control the disease, sickle cell patients use a combination of methods such as increasing folic acid intake, drinking plenty of water, avoiding extreme temperatures and avoiding excess exertion and stress. African-Americans, Sickle Cell Anemia and Malaria 1 out of 400 African-Americans have sickle cell. Which means that 8% of African- Americans carry the sickle cell trait. However, sickle cell is not exclusively an African-American issue. Scientists conclude that sickle cell is a gene mutation that may have developed as a defensive mechanism against malaria.

Research has shown that those with the trait have a higher than average survival rate in malaria infected regions than those who do not carry the trait. What is Malaria? Malaria is a life-threatening disease transmitted by the female Anopheles mosquito. The cause of the Malaria is a parasite called plasmodium. Almost 40% of the world's population is at risk for Malaria as ninety percent of Malaria deaths occur south of the Sahara. Sadly, Malaria kills an African child every 30 seconds.

Malaria and Sickle Cell Scientific studies seem to suggest that the sickle cell gene protects against malaria. A University of Michigan study finds that children with sickle cells had a lower rate of malarial infection than those with normal cells. In an experiment, all but one of the 15 volunteers who did not have the gene injected with malaria developed the disease. On the other hand, only two of the 15 volunteers with sickle cell developed the disease.

Remarkably, the sickle cell trait is confined to areas where malaria is present or within populations from affected areas. The illustration below shows the malaria life cycle Courtesy of "Roll Back Malaria" The World Health Organization Scientists also contend that sickle cell did not develop to fight malaria itself. However, thanks to natural selection those with the gene have a better chance of survival against the deadly infection.

Therefore, those who had the gene lived to have children who carried the gene, and their children had children who carry the gene, and most of those without the gene did not survive to produce children. Furthermore, those with two sickle cell genes died from complications of the sickle cell disease itself and eventually more people with one normal gene and one sickle cell gene survived. Conclusion It appears that the sickle cell trait was not solely formed to be a barrier against malaria as originally thought by most.

However, natural selection has evolved those in affected regions in such away that those with the abnormal trait enjoy a longer life than those who do not have the trait. The trend has been that.