Sickle Cell Mutation

Sickle Cell Mutation

Commonly found among inhabitants of West Africa and African Americans, sickle cell anemia is an inherited blood disorder that arises from a single amino acid substitution in one of the component proteins of hemoglobin (Boyd and Silk, 2006: 42). Instead of having a more typical rounded shape, red blood cells of an affected individual have a sickle form (McHenry, 2008). Red blood cells with normal hemoglobin move easily through the bloodstream, delivering oxygen to all of the cells of the body, however sickling blood cells tend to have a harder time passing through the body’s blood vessels, due to their abnormal shapes caused by the hemoglobin, which in turn leads to clogging and the deprivation of the body’s tissues and organs of the oxygen they need to stay healthy (McHenry, 2008). Deprivation of oxygen being carried to the organs of the body can also result in organ failure. Though deadly, sickle cell anemia is still prevalent among the worlds population varying in frequency in different regions depending on the effects of natural selection, such as with the incidence of malaria where the sickling allele occurs more often.

A single substitution in the primary sequence of amino acids in the hemoglobin molecule of an individual results with the condition commonly known as sickle cell anemia (Boyd and Silk, 2006: 42). The amino acid sequence of an affected individual is identical to that of a normal individual, however the difference lies in that one amino acid is substituted with another. The actual mutation, however, takes place in the DNA, which is then translated to this amino acid substitution. According to Boyd and Silk (2006), individuals with this disease are homozygous for a gene that codes for one variant of hemoglobin, the protein that transports oxygen molecules in red blood cells. Hemoglobin is made up of two different protein subunits, labeled α (alpha) and β (beta) (Boyd and Silk, 2006: 406). The DNA sequence for the most...