why sickle cell is common in black communites than in white communities?
600548
Because it's a genetically recessive disease; both parents need to have it in order to have a child with the disease. Also, sickle cell anemia hurts your body's capacity to carry oxygen, so people afflicted tend to have less children, so it tends not to spread amongst the population.\n\nBoth these make it quite rare in the West. But in some parts of Africa, where malaria strikes and kills millions of people, sickle cell anemia is actually a good disease to have, because it protects you against malaria. So people with it actually have *more* children than people without, so the damaged gene spreads and survives!
787468
for one African-Americans are more @ risk for heart disease because of our previous and current diets.\n\nAlso African-Americans are more @ risk for sickle cell.\n\n/doc
188316
In the red cells of the mammalians, the lack of nucleus allows more room for hemoglobin and the biconcave shape of these cells raises the surface and cytoplasmic volume ratio. These characteristics make more efficient the diffusion of oxygen by these cells. In so-called "sickle-cell anaemia", erythrocytes become typically sickle-shaped. With the electron microscope, biologists saw that red cells can have different shapes: normal (discocyte), berry (crenated), burr (echinocyte), target (codocyte), oat, sickled, helmet, pinched, pointed, indented, poikilocyte, etc. The mean life of erythrocytes is about 120 days. When they come to the end of their life, they are retained by the spleen where they are phagocyted by macrophages.
585730
What causes sickle cell disease? \n\nSickle cell disease, a group of blood disorders, is inherited, passed from parent to child. Children with sickle cell disease have two defective genes, one from each parent. \n\nA child born with sickle cell trait inherited one defective gene from one parent, and a normal gene from the other parent. These children don't have sickle cell disease but are carriers of the defective gene and may pass it on to their children.\n\nHow is it treated? \n\nThe best possible treatment for a person with sickle cell disease is a partnership between the affected family and a team of health professionals. Successful treatment requires: \n\nEarly diagnosis using infant screening (shortly after birth). \nPreventive antibiotic treatment and immunizations starting at 3 to 4 months of age. \nAn aggressive pain treatment plan. \nConsultation with doctors skilled in the care of patients with sickle cell disease. In severe cases, doctors may recommend regular blood transfusions, drug treatment with hydroxyurea, or (rarely) bone marrow transplant.
900741
The main blood groups of concern here are the ABO and Rhesus. \n\nThe rarest ABO group is AB which is found in ~ 3% of the UK population.  It actual frequency does vary depending on you racial background.\n\nThe Rhesus groups are generally classified as +'ve or -'ve.  You could see this written as DD or Dd for +'ve and dd for -'ve.  Rh + occurs in about 92% of the population and Rh- in the remaining 6%.\n\nThe rarest group would be AB, Rh- which would be found in about 1 in 500.\n\nHowever, the Rhesus system is more complex that simple +'v or -'v.   It can be broken down  into 6 or more Rh groups.  The rarest of these is written as Rh2Rh2 and occurs  in ~1%.     \n\nThere are many other blood groups.  Some can be important in transfusion but I will leave it here.
10009
Part of it has to do with a persons race. The other part has to do with a persons health.
352787
There are certain identifiable characteristics that can be found in some blood samples. The most prominent example is Sickle Cell anemia.  \nThat's just from blood. However, from DNA markers, it is possible to identify certain genomes that would give you a pre-disposition to certain races.  It may not be a definative race, but it could narrow down possibilities until you can come up with a high probability.
190271
People actually love blacks and often try to mimic our style and culture.(Contrary to the other answer you received). Don't look anywhere in particular, just out your window and you will see what I mean. People perish for lack of knowledge, and thats what its all about. Lack of knowledge of other cultures. There are stereotypes of disease and sickness from Africa, which can be said of just about every other nation. Again, just be yourself and don't worry about trying to integrate.
716160
The "sickle cell" gene (technically, allele) is a result of a mutation that modifies the shape of red blood cells. It's what is known as an incompletely recessive trait, meaning that a person with one copy of the sickle cell allele and one copy of the normal allele has mostly normal red blood cells with a few sickled ones. This state has been shown to give the person carrying it resistance to malaria, a common and often fatal disease in tropical regions, particularly Africa. \nThus in Africa, the sickle-cell allele would have been rendered more common by natural selection, since being resistant to malaria was a huge advantage. The children of two people carrying the sickle-cell trait have a 25% chance of receiving both sickle-cell genes from their parents, which is known as sickle-cell anemia. \nIt's not that only people of African descent can have sickle-cell anemia, but through selection the responsible gene was made more common because of malaria resistance. The same would not be the case in areas of the world where malaria was not common; which is why people whose ancestors came from other places are not as likely to have two parents carrying the sickle-cell trait.
783451
The 2 alleles responsible for whether normal or sickle red blood cells are HbA and HbS. The HbS allele (sickle cell gene) is recessive but more exactly, that allele is incompletely recessive (i.e. in the heterozygote HbAHbS, a few sickle red blood cells are still present besides the normal one, shows that HbS gene are still expressed at small rate). The HbS induces the polymerization of hemoglobin in red blood cells, leading to abnormal sickle shape of the cells, making it very difficult for these red blood cells to pass through the blood vessels and stuck there.\n\nOne person is called suffering from sickle cell anemia if they have the HbSHbS form, i.e. the homozygous recessive. In the HbAHbS the few sickle red blood cells are not enough to cause symptoms. \n\nOne interesting thing about this disease is that, while the HbSHbS form would be dangerous because the red blood cells cannot carry oxygen to cells and stuck in the blood vessels, the carriers (HbAHbS) would have advantage in malaria region. Since the malaria parasite spends parts of its life in red blood cells, these parasite cause the abnormal sickle cells to rupture, moreover, the polymerization of Hb disables the parasites to digest Hb. The white blood cells also kill the parasite better when they come to kill the stuck sickle cells. That why people with HbAHbS form have a higher fitness to the malaria environment than people with normal red blood cells.
928157
You can write on Sickle Cell Anemia...
110246
Sickle cell disease is much more common in certain ethnic groups, but not unheard of in all. Someone who inherits hemoglobin S from one parent and normal hemoglobin (A) from the other parent will have sickle cell trait. (Hemo. S being the one that reduces the oxygen in blood cells)
292556
You probably already know this but populations of humans were never separated well (reproductively or geographic isolation) from one another for significant changes to build up.  That said, I'm sure you know of the sickle cell trait that (to my knowledge) evolved at least twice (Africa and the Indian sub-continent).\n\nOne of the more interesting explaination I've found for skin color changes was described in an excellent article in "Scientific American," October 2002.
503274
it doesnt mater where they came from they will be effected the same wherever they go if they are exposed to the same amount of sun. skin cancer does happen to black people but it is much more common in whites. blacks do have a little bit better protection but the main reason that skin cancer is more common in whites is that they are always trying to tan themselves.
424437
This is true in the United States, on a percentage basis of their total population.\nSome correlation can be found in educational opportunity and income.  Other correlation can be found in lopsided enforcement statistics indicating racial profiling.  Some causes can be found in media influences.\n\nThere is no science that can be brought to bear on social problems, so we thrash about with theories and theories, and no real results-based analysis is ever done.  (Same as education problems, see this week's Time Magazine, Apr 17)\nThis country was born with a defect of racial injustice, and although legally this defect has been removed, it still has not healed.
260846
Where are you from.  Ive learned in Nursing school that people in malaria stricken countries develop different blood cells that can deal with malaria and sometimes are born with different blood cells that make them naturally resistent to Malaria
382039
Hemoglobin C is a variant of hemoglobin that is not normally present.  It is a result of a mutation in hemoglobin genes and cannot be prevented or treated.  The result is a chronic anemia which may, for the most part, be asymptomatic (undetected) unless another factor brings it to the surface (e.g. an acute illness, a change of lifestyle, etc). \n\nThe effect of having Hemoglobin C in your red blood cells is that they will tend to break down more readily than those with normal hemoglobin, putting your RBC production rate in overdrive.  Normally, this will go unnoticed, but a situation which puts further stress on your RBC production rate will expose the limitation.  This will cause episodes of jaundice (yellow discoloration of the skin and mucous membranes) and fatigue under stressful conditions. \n\nOn a lighter note, because of the subtle chemical differences in Hemoglobin C structure, people who carry it are almost immune from contracting malaria. \n\nOne additional comment:  the percentage of you HbC suggests that this MAY not be the only hemoglobinopathy present in this case.  It is common for some HbC individuals to also have a thalassemia.  It could be a good idea to have that checked out, especially if you have African/Mediteranean lineage.