Monday, April 6, 2009
Search: sickle cell anemia
Why: In elementary school, our PE teacher Mr. Burness always spouted off a bunch of ailments that - should we have any - would preclude us from running the mile/doing 6-part squat thrusts/playing 4-square. One of them was sickle cell anemia.
Answer: A blood disorder that affects the hemoglobins in red blood cells that carry oxygen through the body. It occurs when a person inherits 2 abnormal genes (1 from each parent) that cause RBCs to change shape, from disc-like to crecent-like. RBCs with the normal hemoglobin (HbA) move easily through the blood, but RBCs with the abnormal gene (HbS) become sticky, stiff, and fragile. RBCs containing HbS can go back and forth between being shaped normally and being sickle-shaped until they eventually become sickle-shaped permanently. Instead of moving through the bloodstream easily, these sickle cells can clog blood vessels and deprive the body's tissues and organs of the oxygen they need to stay healthy. People with the disease can also experience complications from impaired blood circulation and infection-fighting problems.
The More You Know: 1/3 of all aboriginal inhabitants of Sub-Saharan Africa carry the gene because in areas where malaria is common, there is a survival value in carrying only 1 sickle-cell gene. The prevalence of the disease in the U.S. is approximately 1 in 5,000 (about 70,000 people), mostly affecting African Americans.