Sunday, October 2, 2011

Sickle Cell Disease


Nii Wilson, The Sickle Cell Athlete 

Overview 

Sickle Cell, simply put, is the deformation of various red blood cells due to a alteration of a amino acids in the hemoglobin protein. These deformed red blood cells create a sickle, or crescent shaped. These sickle cells cause issues within the cardiovascular system, often blocking small vessels, preventing parts of the body from obtaining oxygen. These sickle cells are able to prevent tissues and organs from obtaining the oxygen they need through the block vessels. More importantly sickle cells don't function as a normal blood cell would, transporting oxygen, they break down prematurely and can cause a low red blood cell count, anemia. 

The History of Sickle Cell

Considering that the HbS gene,responsible for sickle cell disease, was not recorded in African literature until the late 1870's. The reason for this may be contributed to sickle cell having symptoms similar to other Tropical African disease, also, blood usually wasn't taken and examined, lastly, most individuals with sickle cell died in their infancy, long before a doctor regularly see them. 

Prior to the 19th century, African tribes were completely familiar with the symptoms of sickle cell that they named the disease. The names, complex and African, often contained repetitive syllable, said to exemplify the repetitive pain of the victim. In a less scientific way.  For example, if an infant were to die in a village from the disease, many believe the infant was actually preventing an evil demon from entering the village.   

Symptoms

Symptoms of sickle cell disease, consist of multiple cardiovascular and physical issues:

Anemia-A lack of red blood cells, the sickle cells breakdown ten times faster than normal red blood cells, leaving an individual with low red blood cell count.

Episodes of Pain-Pain can be cause by the blockage of small blood vessels can cause pain all through the body. These pains are called crisis, said crisis's can develop within minutes and cause an individual to need hospitalization. 

Hand-Foot Syndrome- The swelling of hands and feet due to lack of blood supply cause by sickle cells blocking of blood vessels. This blockage doesn't allow sufficient blood supply to go to the extremities. 

Frequent Infections- Sickle Cell causes damage to the spleen, the spleen is an organ in the body that fights infections. In infants sickle cells can be life threatening, thus, infants with the disease are often prescribed antibiotics. 

Delayed Growth- Red blood cells provide the needed oxygen and nutrients to the body. Sickle cells don't provide these nutrients to the body and result in delayed growth.

Vision Problems- Within the eye, there are tiny blood vessels that can become blocked by the odd shaped sickle cells. This blockage damages the eye's tissue and functionality. 

Causes

Within the 11th pair of chromosomes the HBB gene lies responsible for sickle cell. When the HBB gene is mutated sickle cell disease is formed. This mutated HBB gene is a recessive trait, allowing it to be carried through individuals without notice.

Hemoglobins consist of 4 proteins subunits, alpha-globins and beta-globins. The HBB gene provides instructions to make the beta-globins. Multiple versions of beta-globins are produced by the mutated HBB gene. Certain mutated forms of beta-globin  causesing the hemoglobin to deform the red blood cells and create the sticky, crescent shaped cell. 

The inheritance of sickle cell is simple. If both of your parents are carriers then you have a 50% chance of becoming a carrier and a 25% chance of suffering from it yourself. This is displayed in figure 1 below. If one of your parents has sickle cell and the other is a carrier then you have a 50% chance of becoming a carrier and a 50% chance of suffering from the disorder.  If both of your parents suffer from sickle cell, you have a 100% chance of suffering form it too. 

Figure 1, The inheritance pattern of sickle cell. 

Other Data

Diagnostics- Hemoglobin electrophoresis, isoelectric focusing, chromatography.

Hemoglobin Electrophoresis is the most common diagnostic test for sickle cell. It takes advantage of the fact that different hemoglobins have different electrical charges. The electrophoresis sends electrical currents through a sample of control blood and test blood. These electrical currents  cause hemoglobins to seperate and form bands. After this process, the control blood is compared against the test,  allowing doctors to see the types and quantities of hemoglobin in the blood. 

Treatment- There is no cure for sickle cell. But there are treatments for the many symptoms caused by the sickled cells. Most preventing the clots withing vessels. 

Prevention- You can't prevent it. But you can prevent your offspring from having it, by not having offspring.

Research- Charities and other organizations are researching sickle cell. their research helps improve the lives of sickle cell patients. An example of one organization is the William E. Proudford Sickle Cell Fund Incorporated. 


Research Project Dedicated to Sickle Cell

Boston University's Center of Excellence in Sickle Cell Disease The SickleGen Project
The focus within this University's Project is to investigate how congruencies among patients influence their genetic disorders. 




Organizations' Links:




Informative Videos:





Works Cited

Mukerji, Dr. Ishita, Molecular Biology and Biochemistry Department, Molecular Biophysics Program, and Wesleyan University. "About Sickle Cell Disease." About Sickle Cells - Homepage. The Patrick and Catherine Weldon Donaghue Medical Research Foundation., 5 Mar. 2004. Web. 28 Sept. 2011. <http://www.sicklecellinfo.net/index.htm>.

"Sickle Cell Disease - Genetics Home Reference." Genetics Home Reference - Your Guide to Understanding Genetic Conditions. Trans. U.S. National Library of Medicine. 27 Sept. 2011. Web. 28 Sept. 2011. <http://ghr.nlm.nih.gov/condition/sickle-cell-disease>.

Staff, Mayo Clinic. "Sickle Cell Anemia - MayoClinic.com." Mayo Clinic. Web. 28 Sept. 2011. <http://www.mayoclinic.com/health/sickle-cell-anemia/DS00324>.