Sickle cell disorder is by far the commonest inherited disorder in the world and three quarters of cases occur in Africa. In Nigeria, where it affects two out of every hundred children born, it causes suffering for innumerable patients and their families. However, despite its importance, until now there has been no dedicated sickle cell center in Africa. This is partly because the very scale of the problem makes it difficult to see how to start.
Sickle cell disorder is an inherited haemoglobin disorder comprising sickle cell anaemia (Hb SS) and some less prevalent but related conditions such as sickle haemoglobin C disorder (Hb SC) and sickle beta thalassaemia (Hb SBthal). The genes for these conditions arose by mutation but proliferated in areas where there is or there was a high incidence of falciparium malaria, the most lethal strain of malaria known to man.
The individual with the sickle cell trait (Hb AS) is protected from sickle cell symptoms and complications by the presence as well of Hb A. He is largely protected from death caused by malaria, especially in early childhood, by the presence of Hb S. Thus he enjoys the best of both worlds and is naturally better adapted to the malaria infested environment than the individual with the normal Hb AA who is more liable to childhood death from malaria, or the sickle cell affected one with Hb SS in whom malaria easily induces a lethal degree of anaemia.
Hence, more persons with Hb AS survived to reproduce and pass the Hb S gene on to their progeny. Thus, the prevalence of sickle trait (Hb AS) increased in each successive generation. Falciparum malaria therefore encouraged the expansion of the gene within the population by conferring on healthy carriers a selective survival advantage. Conversely, when populations emigrated to a non-endemic malaria zone the incidence of the Hb S gradually waned over many generations owing to the absence of the selective survival and reproductive advantage. This phenomenon is demonstrated in South Africa, in the West Indies and in the United States of America.
While the Bantus in African countries north of the Zambesi River have a significant incidence of sickle cell disorder, the Bantus in temperate malaria-free South Africa have no significant incidence of SCD.
They are reputed to have migrated to South Africa about 2,000 years ago and the prevalence of the sickle trait is less than 0.5% in their population. In African-Americans and African-West Indians 'Who migrated relatively recently, only 300-400 years ago, the frequency of the sickle trait among them is 8% and 10% respectively.
The anaemia is a serious genetic disease in which the body makes sickled shaped cells like a ''C'' . Normal red blood cells are disc shaped and look like doughnuts without holes in the center they move easily through the blood vessels .Normal red blood cells contain hemoglobin (H.B.S.) this is iron rich protein gives the blood its red color and carries oxygen from the lungs to the rest of the body. Sickle cells contain an abnormal hemoglobin that are at risk of having children with sickle cell disorder.
Sickle shaped cells do not move easily through the blood vessels. They are stiff and sticky and tend to form clumps and get stuck in the blood vessels ; the clumps of sickle cells block blood flow in the blood vessels that lead to the limbs and organs. Blocked blood vessels can cause pains, infections and organ damage due to blood deprivation to tissues and organs. Sickle cell anaemia is most common in people whose families come in from Africa south or central America, Caribbean islands ,Mediterranean countries India and Saudi Arabia.
Sickle cell anaemia is only one type of anaemia. Anaemia is a condition in which the blood has lower than normal number of red blood cells. This condition also occurs if the red blood cells do not have enough hemoglobin .Red blood cells are made in the spongy marrow inside the large bones of the body. Bone marrow is always making red blood cells to replace the old ones. They carry oxygen and remove carbon dioxide from the body.
Normal red blood cells last about 120 days in the bloodstream and then die. In sickle cell anaemia a lower-than normal number of red blood cells occurs because sickle cells do not last very long, they usually die after only about 10 - 20 days. And the case of sicklers, the bone marrow cannot not make new red blood cells fast enough to replace the dying ones ,sickle cell anaemia in an inherited disease lifelong disease. People who have the disease are born with it. They inherit two copies of the sickle cell gene-one from each parent. People who inherit a sickle cell gene from one parent and a normal gene from the other parent have a condition called sickle cell trait. Sickle cell trait is different from sickle cell anaemia. People who have sickle cell trait do not have the disease but they have one of the genes that can cause it like people who have sickle cell anaemia.
To know more and help in the fight against sickle cell, kindly visit, Dabma Sickle cell Foundation
Sickle shaped cells do not move easily through the blood vessels. They are stiff and sticky and tend to form clumps and get stuck in the blood vessels ; the clumps of sickle cells block blood flow in the blood vessels that lead to the limbs and organs. Blocked blood vessels can cause pains, infections and organ damage due to blood deprivation to tissues and organs. Sickle cell anaemia is most common in people whose families come in from Africa south or central America, Caribbean islands ,Mediterranean countries India and Saudi Arabia.
Sickle cell anaemia is only one type of anaemia. Anaemia is a condition in which the blood has lower than normal number of red blood cells. This condition also occurs if the red blood cells do not have enough hemoglobin .Red blood cells are made in the spongy marrow inside the large bones of the body. Bone marrow is always making red blood cells to replace the old ones. They carry oxygen and remove carbon dioxide from the body.
Normal red blood cells last about 120 days in the bloodstream and then die. In sickle cell anaemia a lower-than normal number of red blood cells occurs because sickle cells do not last very long, they usually die after only about 10 - 20 days. And the case of sicklers, the bone marrow cannot not make new red blood cells fast enough to replace the dying ones ,sickle cell anaemia in an inherited disease lifelong disease. People who have the disease are born with it. They inherit two copies of the sickle cell gene-one from each parent. People who inherit a sickle cell gene from one parent and a normal gene from the other parent have a condition called sickle cell trait. Sickle cell trait is different from sickle cell anaemia. People who have sickle cell trait do not have the disease but they have one of the genes that can cause it like people who have sickle cell anaemia.
To know more and help in the fight against sickle cell, kindly visit, Dabma Sickle cell Foundation
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