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Shantal Al HabibIB Biology HL 22 December 2015Sickle cell anemia & malariA: are they linked and how?

Sickle cell anemia is the commonest genetic disease in the world and is caused by a base substitution mutation in which GAG is transcribed as GTG and valine instead of glutamic acid is translated It is a disease in which the bodys red blood cells turn into a sickle shape and carry less oxygen to the rest of the body parts.

What is sickle cell anemia?

The longevity of the cells is significantly reducedThe body cannot replace blood cells as rapidly and as a result, anemia develops.

Sickle cells block the blood flow because they gather in blood vessels and block the pathway.

It causes pain, organ damage, shortness of breath, headaches, dizziness, coldness in extremities, tiredness and weakness of the body.

It is a very dangerous blood disease that is transmitted by the female Anopheles mosquitoAfter biting, a parasite enters and lays a dormant in the liverThen the new parasite infect more red blood cells and the number increases

Malaria causes organs dysfunction and can easily be fatal if it was not treated since the early stages.Far too many people die because of malaria.Famous victims are: Alexander The Great, and George WashingtonWhat is malaria?

The Lifecycle of MalariaWhen the infected mosquito sucks human blood (bite), it injects saliva to stop the blood from clotting. The saliva enters the human blood system and targets the liver. After duplicating, it targets red blood cells. The cell become sticky and eventually bursts

Sickle cell anemia and resistance to malariaOn a vocational Oxford University Expedition toMount Kenya, Anthony Clifford Allison took blood samples from over 50 thousand individuals and analyzed them.He noticed the following trend;

From this disparities, he noticed that the places where high frequencies of sickle cell anemia were observed, were the breathing ground for the mosquitos that cause malaria then the idea of linkage between the two diseases arose and a question was being asked .

He tested out his hypothesis and looked at the malaria parasite load in each sample.After that, he looked for the sickle cell anemia character.He found that the individuals have sickle cell anemia, have very few malaria parasite.This suggested that sickle cell anemia protects from malaria How did he test out this theory?Could sickle cell and malaria be connected? And if so, how?

correlation

Source: http://biogenevent.weebly.com/uploads/2/5/3/8/25386649/3806036_orig.jpg

Heterozygote advantage:A person who carries a heterozygous allele, has greater fitness towards Malaria and develops resistance to the malarial parasite.

How does sickle cell trait protect from malaria?

The similarities in the effects both of these diseases have, helps the organism adapt.

malaria is harmful because of the release of toxic hemes for capillaries. The mechanism we use to fix free hemes can work against malaria. So when an organism is exposed to malaria, it knows how to fight against it and avoid the more toxic effects of malaria.

Although Sickle-cell Anemia is a mortal genetic disease, this disadvantageous phenotype is helpful in some cases, like malaria.

EVOLUTION??

It is a form of evolution because natural selection allowed this mutated allele, which is mortal, to continue existing.Is one dangerous disease preserved to act as a resistant to another?10

The answer for the question is based solely on the person. Look at the question below and answerIs it a casual link or a correlation?

Bibliography:Instituto Gulbenkian de Ciencia. "Mystery solved: How sickle hemoglobin protects against malaria." ScienceDaily. ScienceDaily, 29 April 2011.

Lam, Peter. "Malaria: Causes, Symptoms and Treatments."Medical News Today. MediLexicon, Intl., 27 Nov. 2015. Web.20 Dec. 2015.

Malaria and Sickle Cell Anemia HHMI BioInteractive Video. Anthony Clifford Allison, Matthew Heeney, Sean Carroll. Hhmi.org, 2014. YouTube video.