User:Wulf.174/sandbox

10/01/2014 https://en.wikipedia.org/wiki/Sickle-cell_disease There should be more ties to how sickle-cell disease is shaping certain African populations, and how these populations no longer have a high rate of malaria like they previously did. There are only brief areas on the page that mention how malaria and sickle-cell disease relate to each other, but I believe there should be a bigger section that ties it together. As far as the history section, the most recent dates are from the 1940's-50's. I'm sure something has happened or been discovered about sickle-cell disease since then.

What have you found that could help make that improvement to the history section?

Larson.309 (talk) 18:19, 12 October 2014 (UTC)

edit: There have been studies in Africa that show a significant decrease in infant mortality rate, ages 2-16 months, because of the sickle-cell trait. This happened in areas that were known to be predominant areas of malarial cases.

https://en.wikipedia.org/wiki/Malaria There should be more added about how sickle-cell disease is lowering the mortality due to malaria. People heterozygous for the sickle-cell gene can still get malaria, but they are far less serious than someone who is not a carrier of the sickle-cell trait. For instance, the article cited shows a study of children who were between 2-16 months old, had a significantly low mortality rate if they carried the sickle-cell gene.

Sept. 2014 Topic: How sickle-cell traits cause natural selection in humans

Allison, A C., "Protection Afforded by Sickle-cell Trait Against Subtertian Malarial Infection." British Medical Journal 4857.1 (1954): 290-294. NCBI. Web. 12 September 2014.

Many Africans carry the sickle-cell trait and are heterogeneous for it without having sickle-cell anemia. Very few are homogeneous recessive for the sickle-cell trait. It was noted in this article that those with the sickle-cell trait showed a smaller percentage showed malaria in their blood slides. This could mainly be due to the sickle-cell carriers having different sized spleens. It was also found that if children who carry the sickle-cell trait do get malaria, they get it less often and not as severe as the non carriers. It was also mentioned that many of the tribes that are high in sickle-cell traits are malarious areas.

Ackerman, H., Usen, S., Jallow, M., Sisay-Joof, F., Pinder, M. and Kwiatkowski, D. P. (2005), "A Comparison of Case-Control and Family-Based Association Methods: The Example of Sickle-Cell and Malaria." Annals of Human Genetics 69: 559–565. Web. 12 September 2014.

In this study, children with malaria were tested for the gene that carries the sickle-cell trait. It was found that in most of the children with the most severe cases were not carriers of the sickle-cell trait with a very high percentage of homogeneous dominant. In the other cases of malaria that weren't as severe, but still bad, most of them, too, did not carry the sickle-cell trait. The parents of the children all had the genotypes of the general population.

Aidoo, Michael, Dianne J Terlouw, Margarette S Kolczak, Peter D McElroy, Feiko O ter Kuile, Simon Kariuki, Bernard L Nahlen, Altaf A Lal, and Venkatachalam Udhayakumar. "Protective Effects of the Sickle-cell Gene Against Malaria Morbidity and Mortality." The Lancelet. 359.9314 (2002): 1311-1312. Web. 12 September 2014.

Children 2-16 months of age with the heterozygote gene for sickle-cells were found to have a significantly smaller mortality rate compared to others in the population. The mortality rate included all deaths, not just those caused by malaria. They concluded that the heterozygous gene helped those children live in a time when they would have been more susceptible to get malaria without being immune yet and not strong enough to fight it off.

Williams, Thomas N, Tabitha W Mwangi, David J Roberts, Neal D Alexander, David J Weatherall, Sammy Wambua, Moses Kortok, Robert W Snow, and Kevin Marsh. "An Immune Basis for Malaria Protection by the Sickle Cell Trait." PLOS Medicine. 10.1371 (2005). Web. 12 September 2014.

It was found that immunity to malaria increased from 20% to 60% during the first 10 years of a child's life who has the sickle-cell trait. The immunity then drops down to 30% after 10 years old.