Sickle Cell Anemia, Human Variation And Race

7 Pages 1830 Words

o inherited the HbS gene from both parents) may however develop sickle-cell disease. There is a wide clinical variety within the sickle-cell disease or SS disease. Even in the same environment complications may vary from moderate to severe. Factors that influence the variation include “the coincidence of alpha thalassemia or heterocellular persistence of HbF and environmental conditions” (Serjeant, 2). Clinical disease symptoms are linked to oxygen consumption. Individuals with SS hemoglobin demand greater oxygen, usually with exercise, molecules “become deoxygenated; shape change follows, which brings on a sickling crisis”(Molnar, 141). A host of factors including the age, occupation, diet, and geographic location all influence the risk of sickling crisis. Clinical manifestations of sickling crisis include moderate to severe hemolytic anemia (which can lead to premature gall stones in some patients), increased of certain infections, organ damage and failure and recurrent pain episodes (Eckman, 2). Unfortunately, a high mortality rate is associated with the SS homozygote during aplastic crisis or splenic sequestion crisis associated with tissue infarction (Eckman, 2). The “average life expectancy is about forty years in the United States and much lower in Africa (Molnar, 141).
In many West African populations HbS and HbC are present wi...