The following sections of this BookRags Literature Study Guide is offprint from Gale's For Students Series: Presenting Analysis, Context, and Criticism on Commonly Studied Works: Introduction, Author Biography, Plot Summary, Characters, Themes, Style, Historical Context, Critical Overview, Criticism and Critical Essays, Media Adaptations, Topics for Further Study, Compare & Contrast, What Do I Read Next?, For Further Study, and Sources.
(c)1998-2002; (c)2002 by Gale. Gale is an imprint of The Gale Group, Inc., a division of Thomson Learning, Inc. Gale and Design and Thomson Learning are trademarks used herein under license.
The following sections, if they exist, are offprint from Beacham's Encyclopedia of Popular Fiction: "Social Concerns", "Thematic Overview", "Techniques", "Literary Precedents", "Key Questions", "Related Titles", "Adaptations", "Related Web Sites". (c)1994-2005, by Walton Beacham.
The following sections, if they exist, are offprint from Beacham's Guide to Literature for Young Adults: "About the Author", "Overview", "Setting", "Literary Qualities", "Social Sensitivity", "Topics for Discussion", "Ideas for Reports and Papers". (c)1994-2005, by Walton Beacham.
All other sections in this Literature Study Guide are owned and copyrighted by BookRags, Inc.
Sickle cell anemia is an inherited blood disorder striking almost exclusively individuals who are of African descent. Sickle cell anemia is a recessive trait, meaning that an individual only has the disease if he or she receives a gene for it from each parent. Individuals who have only one faulty gene are considered to have the sickle cell trait, but not the disease. Interestingly enough, sickle cell trait has been studied, and appears to provide some protection against other diseases, such as malaria (a disease which is rampant within the countries of Africa, where the sickle cell gene is believed to have originated).
The oxygen-carrying component of the red blood cell is called hemoglobin. In sickle cell anemia, a single incorrect amino acid is substituted at one point within the structure of the hemoglobin molecule. This results in red blood cells which have a characteristic sickle (or half-moon) shape, instead of the usual indented disc shape. These misshapen red blood cells are prone to damage, and are destroyed more quickly than are normal red blood cells, resulting in a low red blood cell count (anemia). The sickled cells also tend to move sluggishly through small vessels, sometimes blocking those vessels for a period of time. When a vessel is blocked, the tissues or organs usually served by that vessel are deprived of oxygen, resulting in damage and pain. Episodes of such pain are referred to as "crises." These crises can be precipitated by infection and by low-oxygen states.