Pleiotropy to have protein. Sickle cell anemia is a genetic disease that causes deformed red blood cells with a rigid, crescent shape instead of the normal flexible, round shape. It is caused by a change in one nucleotide, a point mutation in the HBB gene. The HBB gene encodes information to make the beta-globin subunit of hemoglobin, which is the protein red blood cells use to carry oxygen throughout the body. Sickle cell anemia occurs when the HBB gene mutation causes both beta-globin subunits of hemoglobin to change into hemoglobinS (HbS). Sickle cell anemia is a pleiotropic disease because the expression
Red blood cell blood circulation for about 100 to 120 days (and 80 to 90 days in a full term infant). At the end of their lifespan, they are removed from circulation. In many chronic diseases, the lifespan of the red blood cells is reduced. Erythropoiesis is the process by which new red blood cells are produced; it lasts about 7 days. Through this process red blood cells are continuously produced in the red bone marrow of large bones. (In the embryo, the liver is the main site of red blood cell production.) The production can be stimulated by the hormone erythropoietin (EPO),