Saturday, September 19, 2015

Do You Really Know About Sickle Cell Disease? (Part 2)

The origin of the mutation that led to the sickle-cell gene was initially thought to be in the Arabian Peninsula, spreading to Asia and Africa. It is now known, from evaluation of chromosome structures, that there have been at least four independent mutational events, three in Africa and a fourth in either Saudi Arabia or central India. These independent events occurred between 3,000 and 6,000 generations ago, approximately 70-150,000 years.  So this just goes to show you that sickle cell disease (SCD) has been around for a very long time, since the 1600’s, and behooves me that the research, therapies, or even a cure has not been developed or discovered for brown people who are affected by this disease.  It is the only disease where the body mutated the red blood cells to preserve the body from malaria in the areas where SCD is known to originate.

The transatlantic slave trade was largely responsible for introducing the sickle cell gene into the Americas and the Caribbean. However, sickle cell disease had already spread from Africa to Southern Europe by the time of the slave trade, so it is present in Portuguese, Spaniards, French Corsicans, Sardinians, and Sicilians, mainland Italians, Greeks, Turks and Cypriots. Sickle cell disease appears in most of the near and Middle East countries including Lebanon, Israel, Saudi Arabia, Kuwait and Yemen.  The condition has also been reported in India and Sri Lanka. SCD is an international health problem and truly a global challenge.

The majority of sickle cell cases occur among African Americans who are either from Africa or can trace their lineage back to Africa. Other populations that the sickle cell gene is common in are located in the Mediterranean, Middle East, and India areas. These geographic locations are also home to the disease of malaria. It is believed that sickle cell anemia originated in these locations in response to malaria. People infected with sickle cell anemia are less vulnerable to malaria. This has caused an environment where people with the sickle cell disease survived due to less mortality from malaria. As the slave trade began, blacks that were transported to areas devoid of malaria no longer had a use for the sickle cell disease and so it became nothing but a debilitating hindrance.

There is a collection of clinical findings that was unknown until the explanation of the sickle cells in 1904 by the Chicago cardiologist and professor of medicine James B. Herrick (1861-1954).  Herrick’s intern Ernest Edward Irons (1877-1959) found "peculiar elongated and sickle-shaped" cells in the blood of Walter Clement Noel, a 20-year-old first-year dental student from Grenada, after Noel was admitted to the Chicago Presbyterian Hospital in December 1904 because he suffered from anemia.

It was not Noel’s only hospital stay, he was readmitted several times over the next three years due to what the doctors assumed to be "muscular rheumatism" and "bilious attacks". Noel completed his studies to become a dentist and returned to the capital of Grenada (St. George's) to practice dentistry. He died of pneumonia (which is a common reason of death for those living with SCD today) in 1916 and is buried in the Catholic cemetery at Sauteurs in the north of Grenada.

The disease was named "sickle-cell anemia" by Vernon Mason in 1922. However, some elements of the disease had been recognized earlier: A paper in the ''Southern Journal of Medical Pharmacology'' in 1846 described the absence of a spleen in the autopsy of a runaway slave.  This is common for most who have the SS hemoglobin, for the spleen to shrivel up like a raisin and is non-functional from birth.  However, those living with SC hemoglobin like myself the spleen is oversized and non-functional and will continue growing in the body until it ruptures.  I’ve experienced my spleen rupturing!  It grew to the point that it was beginning to move other organs around it, pushing to make more room for itself.  My spleen was removed and it was white and gray in color while the other organs around it were red and functioning properly.  It was the size of a premature baby, when a normal healthy spleen should be red like the organs around it and the size of a fist.

The African medical literature reported this condition in the 1870s, when it was known locally as ''ogbanjes'' ("children who come and go") because of the very high infant mortality rate caused by this condition. A history of the condition tracked reports back to 1670 in one Ghanaian family. Also, the practice of using tar soap to cover blemishes caused by sickle-cell sores was prevalent in the black community.

Linus Pauling and colleagues were the first, in 1949, to demonstrate that sickle-cell disease occurs as a result of an abnormality in the hemoglobin molecule. This was the first time a genetic disease was linked to a mutation of a specific protein, a milestone in the history of molecular biology, and it was published in their paper "Sickle Cell Anemia".

~By Tina Kay 

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