Sickle cell anemia - Essay Example

value to carrying a single sickle-cell gene in these areas because people with only two alleles of the gene are much less likely to fall victim to malaria (Kwiatkowski, 2005). The condition is characterized by the shape of the individual’s red blood cells, which tend to adopt a rigid, abnormal ‘sickle’ shape to them that decreases the cell’s flexibility and can create a number of complications throughout the body as a result. This occurs as a result of a mutation in the hemoglobin gene and it affects approximately 1 in 5,000 Americans, most of who are of African American descent.

The life expectancy for people with sickle cell anemia is shorter than normal averaging 42 for men and 48 for women (Platt, Brambilla & Rosse, 1994). The purpose of the present research is to identify the genetic origins of this illness and the affects it can have upon the body. There are a number of different forms of the disease which are classified based upon the mutations present within the blood. Sickle cell anemia is the term used to specifically apply to those individuals who present homozygosity for the mutation (Green et al, 1993).

In these individuals, long-chain polymers of HbS have the effect of changing the normally smooth, donut-like shape of the red blood cells to a more spiked and rigid shape that makes the cell more susceptible to breakage. People who are heterozygous for the illness are generally carriers, having only one sickle gene and one normal gene that generally makes up for the deficits of the sickle gene. However, when the ‘normal’ gene is also abnormal in some way, other forms of the illness can manifest, typically referred to as compound heterozygous (Green et al, 1993).

The sickling effect is caused by a point mutation in which the glutamic acid, a type of amino acid, is replaced with valine, a hydrophobic amino acid, at the sixth position. When in low oxygen conditions such as being at a high altitude, this causes an aggregation of