#HealthyLifeMatters: Sickle-cell Disease
Nigeria
2
✒️ - By Aan Gray
Sickle-cell disease is a hereditary hemoglobin defect occurring mostly among people of African descent; its symptoms occur in about 1.3% of American blacks, and about 8.3% are asymptomatic carriers with the potential to pass it to their children. The disease is caused by a defective gene that results in the substitution of valine for a glutamic acid in each beta hemoglobin chain. The abnormal hemoglobin (HbS) turns to gel at low oxygen levels, as when blood passes through the oxygen-hungry skeletal muscles. The RBCs become elongated, stiffened, and pointed (sickle-shaped).
These deformed, inflexible cells cannot pass freely through the tiny blood capillaries, and they tend to adhere to each other and to the capillary wall. Thus, they congregate in the small blood vessels and block the circulation. Obstruction of the circulation produces severe pain and can lead to kidney or heart failure, stroke, or paralysis, among many other effects. The spleen removes defective RBCs faster than they can be replaced, thus leading to anemia and poor physical and mental development of the individual. Without treatment, a child with sickle-cell disease has little chance of living to age 2, and even with the best treatment, few victims live to an age of 50.
Sickle-cell disease originated in areas of Africa where millions of lives are lost to malaria. Malarial parasites normally invade and reproduce in RBCs, but they cannot survive in RBCs with HbS hemoglobin. Thus the sickle-cell gene confers resistance to malaria, even in individuals who are heterozygous for it (carry only one copy of the gene) and do not have sickle-cell disease. The lives saved by HbS in Africa far outnumber the deaths from sickle-cell disease, so natural selection favors the per sistence of the gene rather than its elimination. But in North America, where malaria is not prevalent, the lost lives and suffering caused by the sickle-cell gene far outweigh any of its benefits.
Tags: #ScienceWithGray #ScienceOnBuzz #HealthyLifeMatters #Science
Sickle-cell disease is a hereditary hemoglobin defect occurring mostly among people of African descent; its symptoms occur in about 1.3% of American blacks, and about 8.3% are asymptomatic carriers with the potential to pass it to their children. The disease is caused by a defective gene that results in the substitution of valine for a glutamic acid in each beta hemoglobin chain. The abnormal hemoglobin (HbS) turns to gel at low oxygen levels, as when blood passes through the oxygen-hungry skeletal muscles. The RBCs become elongated, stiffened, and pointed (sickle-shaped).
These deformed, inflexible cells cannot pass freely through the tiny blood capillaries, and they tend to adhere to each other and to the capillary wall. Thus, they congregate in the small blood vessels and block the circulation. Obstruction of the circulation produces severe pain and can lead to kidney or heart failure, stroke, or paralysis, among many other effects. The spleen removes defective RBCs faster than they can be replaced, thus leading to anemia and poor physical and mental development of the individual. Without treatment, a child with sickle-cell disease has little chance of living to age 2, and even with the best treatment, few victims live to an age of 50.
Sickle-cell disease originated in areas of Africa where millions of lives are lost to malaria. Malarial parasites normally invade and reproduce in RBCs, but they cannot survive in RBCs with HbS hemoglobin. Thus the sickle-cell gene confers resistance to malaria, even in individuals who are heterozygous for it (carry only one copy of the gene) and do not have sickle-cell disease. The lives saved by HbS in Africa far outnumber the deaths from sickle-cell disease, so natural selection favors the per sistence of the gene rather than its elimination. But in North America, where malaria is not prevalent, the lost lives and suffering caused by the sickle-cell gene far outweigh any of its benefits.Tags: #ScienceWithGray #ScienceOnBuzz #HealthyLifeMatters #Science
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iGrayons
fatoba zion:
nice write up
fatoba zion
nice write up
Thabk you, pal.