Sickle cell anemia is a relatively rare disease in the United States with only about 100,000 Americans affected by the disease, but among those with African ancestry, it is expected that 1 in 365 to contract the disease. The disease causes hemoglobin to be oddly shaped and causes difficulty for the red blood cells that carry hemoglobin to move through blood vessels and deliver oxygen to the body's cells. Poor oxygen delivery can cause organ failure and death in those with sickle cell disease. Why is a deadly disease so common among people of African descent? Anthony Allison, a South African physician and molecular biologist, discovered that subjects with the sickle cell trait were more resistant to malaria than those without the trait. Say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get an original essay Anthony Allison had grown up in the arid highlands of Kenya, but was aware of the malaria problem plaguing the lowlands of the east coast and the area around Lake Victoria. Anopheles mosquitoes carrying the parasite Plasmodium falciparum, which caused malaria in humans, thrived in these warm, humid plains. He became interested in sickle cell anemia after planning to conduct research on the blood types of African tribal peoples. Allison began testing for sickle cell trait in Kenya, and her research found that the frequency of sickle cell trait was higher in people who lived in hot, humid areas where mosquito-carrying malaria was more common. It became clear to Allison that there was a connection between sickle cell anemia and malaria. He conducted further research by collecting blood samples from approximately 5,000 children from different areas of East Africa. He found that children with sickle cell trait had fewer parasites than those without sickle cell trait. The data confirmed his hypothesis that sickle cell trait would be more common in areas where malaria risk was higher due to the commonality of malaria-carrying mosquitoes. Allison's research shows why 1 in 13 people with African ancestry carry the sickle cell trait. Malaria is more common in tropical regions, such as those that exist across much of the African continent. Although having the sickle cell trait helps you resist the potentially deadly effects of malaria, it is only effective if you are heterozygous for the sickle cell trait, meaning you only have one copy of the sickle cell trait. If you are homozygous for sickle cell trait, this leads to having sickle cell anemia, which is a potentially fatal disease in which hemoglobin becomes crescent-shaped and may have difficulty traveling through blood vessels. This can result in a poor supply of oxygen to cells throughout the body, which can be potentially deadly if essential organs are not receiving adequate amounts of oxygen. If you are homozygous and do not have copies of the sickle cell trait, then you do not have any of the protection that the sickle cell trait provides against malaria infections. If each of your parents is heterozygous for the sickle cell trait, their children have a 50% chance of being heterozygous for the trait, and each of your parents has a 25% chance of being homozygous with both copies or no copies of the sickle cell trait . Although it was known that sickle cell trait protects against malaria infections, the mechanism underlying this effect was not understood. Early research suggested that sickle hemoglobin somehow prevented Plasmodium falciparum from infecting red blood cells. It was unlikely to be shaped hemoglobin.
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