Blood disorder sickle cell

How function depends on structure can be seen in the case of the genetic disorder sickle cell anemia. This is a debilitating, sometimes fatal, disease in which red blood cells become distorted ( sickle-shaped ) and interfere with the flow of blood through the capillaries. This condition results from the presence of an abnormal hemoglobin in affected people. The primary structures of the beta chain of normal and sickle cell hemoglobin differ by a single amino acid out of 149 sickle cell hemoglobin has valine in... 

Klug PP, Kaye N, Jensen WN. Endothelial cell and vascular damage in the sickle cell disorders. Blood Cells 1982 8 175-184. 

Sickle cell syndromes are hereditary disorders characterized by the presence of sickle hemoglobin (HbS) in red blood cells (RBCs). 

A family medical history can identify people with a higher-than-usual chance of having common disorders, such as heart disease, high blood pressure, stroke, certain cancers, and diabetes. These complex disorders are influenced by a combination of genetic factors, environmental conditions, and lifestyle choices. A family history also can provide information about the risk of rarer conditions caused by mutations in a single gene, such as cystic fibrosis and sickle cell anemia. 

Among its many other applications, DNA fingerprinting is widely used for the diagnosis of genetic disorders. Cystic fibrosis, hemophilia, Huntington s disease, Tay-Sachs disease, and sickle-cell anemia are among the many diseases that can be detected, enabling early treatment of an affected child. In addition, the U.S. Department of Defense now requires blood and saliva samples from all military personnel. The samples are stored, and DNA is extracted should the need for identification of a casualty arise. 

Various genetic blood disorders including sickle cell anemia and familial thrombophilias (Ch. 2) are associated with stroke. 

Singer, H., Chemoff, A. I., and Singer, L., Studies on abnormal hemoglobin. I. Their demonstration in sickle cell anemia and other hematologic disorders by means of alkali denaturation. Blood 6, 413-428 (1951). 

Pressure affects the solubility of gaseous solutes and gaseous solutions. The solubility of a solute also depends on the nature of the solute and solvent. Temperature affects the solubility of all substances. To learn how a blood disorder called sickle-cell disease can affect oxygen s solubility in blood, read the Chemistry and Society feature at the end of this chapter. 

Not all organisms including humans react in the same way to a given dose of a chemical or an environmental pollutant. In experimental animals, species variation as well as variation in strains within the same species occur. In humans, such factors as serum, red blood cell, immunological disorders, and malabsorption can contribute to differences in their response to environmental stresses. For instance, people with sickle cell anemia will be more susceptible to stresses than normal persons. Individuals with malab-sorptive disorders are also a problem since they may suffer nutritional deficiencies, which in turn may lead to an increased susceptibility to environmental chemicals. 

The Hippocratic view turns out to be the more correct even from a modern molecular perspective, as follows. Consider the modern evidence about the different red blood cell disorders of favism, sickle cell anemia, thalassemia, all believed to be known (at least to some extent) to the ancient Greeks. The point is that it is impossible to use the notion of bad here for the simple reason that these almost certainly conferred an advantage to survival at some stage in history, and prehistory. 

Epoetin alfa has received orphan drug status from the FDA for the treatment of the anemia of prematurity, HIV infection, and myelodysplasia. In the latter case, even very high doses or more than 10(X) units/kg two to three times a week have had limited success. The utility of very high-dose therapy in other hematological disorders, such as sickle cell anemia, still is under study. Highly competitive athletes have used epoetin alfa to increase their hemoglobin levels ( blood doping ) and improve performance. 

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