Essay on 3 Symptoms of Sickle Cell Anemia: Stroke Attacks, Bone Pain, Organ Failure

Watch this captioned video https://youtu.be/Hu-BQR-vkjQ. As you watch, answer the questions below. It will help me if you highlight your answers or put them in bold.

Slide 1

From the video clip, identify three symptoms of sickle cell anemia.

The three symptoms of sickle-cell anemia include the patients suffering from stroke attacks, pain in the bones, and organ failures. Some patients may also encounter acute chest syndrome, as is the case of Davaun in this video.

In the video clip, what does it mean to say that parents could be "carriers" of sickle cell anemia?

As explained in the video, sickle cell anemia is a genetic disease. This further explains what is meant by the parents being carriers of the disease as the parents of the patients may not have the condition even though their children have it. The explanation behind this is that both the mother and the father have sickle cell characters in the DNA. The traits are, however, recessive; hence they do not affect them.

In the video clip, what is puzzling regarding sickle cell anemia and the African American population?

The most surprising thing about sickle cell anemia is that the disease is not rare, considering the number of affected people range between 70,000 and 125,000. This large number is exclusive of the patients from other parts of the world and the immigrants. The occurrence of the disease among African Americans is very high, up to one case in every 500 people.

Slide 2

What is the purpose of hemoglobin (Hb)?

Hemoglobin is a protein found in red blood cells whose function is to carry oxygen to the body tissues and organs. It also aids the transportation of carbon dioxide from the tissues and organs channeling it back to the lungs. If it's level is low, then it means the number of blood cells in your body is low.

Slide 3

From the video clip, why does a mutation that changes the amino acid, glutamic acid to valine, causes sickle cell anemia?

The valine is substituted glutamic acid causes hemoglobin tetramers, which clump into arrays after the tissues are deoxygenated. The clump makes red blood cells to deform into shapes similar to sickle cell. The shapes make the cells inflexible hence they cannot transverse capillary beds.

Slide 4

From the video clip, if both parents are heterozygous, what are the chances a child will be sickle cell homozygous?

In the instances where the parents are heterogeneous, the probability of a child being homozygous is one out of four.

Slide 5

When does the blood of people that carry sickle cell trait (carriers) show some sickle cells?

The blood of individuals with sickle cell anemia shows the cells when oxygen is removed from them. In the video, Tony learned that the addition of chemicals in the blood samples heightened the swift removal of oxygen, making it easy to detect sickle cells.

Slide 6

Which continent has the most sickle cell? Africa, Asia, Europe, North America

Africa has the highest cases of sickle cell anemia.

Slide 7

Malaria is NOT a genetic/inherited disorder. Instead, it is "carried" by _____?

Malaria is carried by Anopheles mosquito.

Slide 8

Identify a continent with both a high frequency of malaria and sickle cell.

Africa is the continent with both high cases of malaria as well as sickle cell DR Caroll explains how Tony discovered this while living in East Africa.

Slide 9

From the video clip, in 1949, Dr. Allison found that in areas of East Africa where there were high areas of sickle cell, there were also high areas of malaria.

Slide 10

What are the names of the two alleles that are "balancing" on this slide?

The two alleles balancing in the slide is HBa and HBs

Slide 11

Which genotype is best in area with malaria? Homozygous HbS, Homozygous HbA, or Heterozygous (HbSHbA)

The best genotype in a region with malaria is Heterozygous (HbSHbA) due to its innate resistance to malaria

Slide 12

In the first video clip, what does the malaria parasite hide from in red blood cells?

From the first clip, the malaria parasite usually hide in the hemoglobin of the red blood cells

In the second video clip, what does the sickle cell "compromise" (prevent) for the malaria parasite?

The second video shows that the sickle cells have simple typo namely A to T the typo in the genes encodes hemoglobin against attacks by the malarial parasite and also prevents the parasite from reproducing

Slide 13

Name a genetic variation other than the sickle cell that protects against malaria.

G6PD aviation allele frequency is another genetic variation that was found to be a protection against malaria

Slide 14

Is G6PD Na genetic/inherited disorder?

G6PD is an inherited disorder as it is passed down from the parents to the children via the x chromosome

Slide 15

Identify a continent where there is a high prevalence of G6PD.

Africa recorded the highest prevalence of G6PD especially in its sub-Saharan regions

Slide 16

Does G6PD have a similar geographic distribution to malaria?

Yes the G6PD (d) allele frequencies were notable in malaria-endemic countries

Part 2 Sickle Cell Simulation 1 -- Mountains

Imagine a small population of humans has migrated to a mountainous region of East Africa, 10,000 years ago. Some humans carry the sickle cell trait (HbS), and some have sickle cell anemia.

Allele Allele Function

HbS allele Sickle cell allele, codes for abnormal hemoglobin shape

HbA allele Wild-type allele, codes for normal hemoglobin

The wild-type allele (HbA) is dominant over the sickle cell allele (HbS). See the table below. In the lab, the humans will be represented as red and gray colors that show their genotype. A yellow phenotype is deadly in this environment. See the table below.

Genotype Visual

Representation of Genotype Phenotype

HbAHbAHbAHbANormal Red Blood Cells (RBCs)

HbAHbSHbAHbSNormal Red Blood Cells (RBCs)

HbSHbSHbSHbSSickle Cell Anemia

Human Generation 1 (Mountains-No Malaria)

Imagine in this population, there are 20 humans, with genotypes and phenotypes shown below.

These humans live in the high-altitude mountains. The climate is dry. (No mosquitoes. No Malaria)

Human Genotype Visual Representation of Genotype Phenotype

1-HbA HbAHbAHbANormal RBCs

2- HbAHbAHbAHbANormal RBCs

3- HbAHbAHbAHbANormal RBCs

4- HbAHbAHbAHbANormal RBCs

5- HbAHbAHbAHbANormal RBCs

6- HbAHbAHbAHbANormal RBCs

7- HbAHbAHbAHbANormal RBCs

8- HbAHbAHbAHbANormal RBCs

9- HbAHbAHbAHbANormal RBCs

10- HbAHbAHbAHbANormal RBCs

11- HbAHbAHbAHbANormal RBCs

12- HbAHbSHbAHbSNormal RBCs

13- HbAHbSHbAHbSNormal RBCs

14- HbAHbSHbAHbSNormal RBCs

15- HbAHbSHbAHbSNormal RBCs

16- HbAHbSHbAHbSNormal RBCs

17- HbAHbSHbAHbSNormal RBCs

18- HbAHbSHbAHbSNormal RBCs

19- HbSHbSHbSHbSSickle Cell Anemia

20- HbSHbSHbSHbSSickle Cell Anemia

In Generation 1, what is the percentage/frequency of the "HbA" allele (# of HbA alleles/40 x 100)? 29/40 x 100 = 72 .5%

In Generation 1, what is the percentage/frequency of the "HbS" allele (# of HbS alleles/40 x 100)? 11/40 x 100 = 27 .5%

Human Generation 2 (Mountains-No Malaria)

The high altitude took a toll on the humans with sickle cell anemia. They did not survive to reproduce. Generation 2 is shown below.

Human Genotype Visual Representation of Genotype Phenotype

1-HbA HbAHbAHbANormal RBCs

2- HbAHbAHbAHbANormal RBCs

3- HbAHbAHbAHbANormal RBCs

4- HbAHbAHbAHbANormal RBCs

5- HbAHbAHbAHbANormal RBCs

6- HbAHbAHbAHbANormal RBCs

7- HbAHbAHbAHbANormal RBCs

8- HbAHbAHbAHbANormal RBCs

9- HbAHbAHbAHbANormal RBCs

10- HbAHbAHbAHbANormal RBCs

11- HbAHbAHbAHbANormal RBCs

12- HbAHbAHbAHbANormal RBCs

13- HbAHbSHbAHbSNormal RBCs

14- HbAHbSHbAHbSNormal RBCs

15- HbAHbSHbAHbSNormal RBCs

16- HbAHbSHbAHbSNormal RBCs

17- HbAHbSHbAHbSNormal RBCs

18- HbSHbSHbSHbSSickle Cell Anemia

In Generation 2, what is the percentage/frequency of the "HbA" allele (# of HbA alleles/36 x 100)? 29/36 x 100= 80.6%5

In Generation 2, what is the percentage/frequency of the "HbS" allele (# of HbS alleles/36 x 100)? 7/36 x 100= 19 .4%

Human Generation 3 (Mountains-No Malaria)

Again, the high altitude took a toll on the humans with sickle cell anemia. They did not survive to reproduce. Generation 3 is shown below.

Human Genotype Visual Representation of Genotype Phenotype

1-HbA HbAHbAHbANormal RBCs

2- HbAHbAHbAHbANormal RBCs

3- HbAHbAHbAHbANormal RBCs

4- HbAHbAHbAHbANormal RBCs

5- HbAHbAHbAHbANormal RBCs

6- HbAHbAHbAHbANormal RBCs

7- HbAHbAHbAHbANormal RBCs

8- HbAHbAHbAHbANormal RBCs

9- HbAHbAHbAHbANormal RBCs

10- HbAHbAHbAHbANormal RBCs

11- HbAHbAHbAHbANormal RBCs

12- HbAHbAHbAHbANormal RBCs

13- HbAHbSHbAHbSNormal RBCs

14- HbAHbSHbAHbSNormal RBCs

15- HbAHbSHbAHbSNormal RBCs

16- HbAHbSHbAHbSNormal RBCs

17- HbAHbSHbAHbSNormal RBCs

In Generation 3, what is the percentage/frequency of the "HbA" allele (# of HbA alleles/34 x 100)? 29 /34 x 100= 85.29%

In Generation 3, what is the percentage/frequency of the "HbS" allele (# of HbS alleles/34 x 100)? five /34 x 100= 14 .71%

Simulation 1 Data Analysis

Now, consolidate your data, so it will be easier to analyze.

Generation Frequency of HbA Allele Frequency of HbS Allele

Generation 1 72.5% 27.5%

Generation 2 80.6% 19.4%

Generation 3 85.29% 14.71%

Which allele decreased in frequency in Simulation 1? Why?

Hbs allele frequency declined in the first simulation. This is because the people in generation 1 lived in high altitude mountains without any cases of malaria. The HbS alleles, therefore, were suppressed and continued going extinct due to natural selection.

Part 3 Sickle Cell Simulation 2 -- Coast

Imagine a small population of humans has migrated to a coastal region of East Africa, 10,000 years ago. Some humans carry the sickle cell trait (HbS), and some have sickle cell anemia.

Allele Allele Function

HbS allele Sickle cell allele, codes for abnormal hemoglobin shape.

HbA allele Wild-type allele, codes for normal hemoglobin

The wild-type allele (HbA) is dominant over the sickle cell allele (HbS). See the table below. In the lab, the humans will be represented as red and gray colors that show their genotype. A yellow phenotype is deadly in this environment. See the table below.

Genotype Visual

Representation of Genotype Phenotype

HbAHbAHbAHbANormal Red Blood Cells (RBCs)

HbAHbSHbAHbSNormal Red Blood Cells (RBCs)

HbSHbSHbSHbSSickle Cell Anemia

What will make Simulation 2 different than Simulation 1, will be the presence of mosquitoes and malaria in this humid coastal region? If a person vulnerable to malaria, dies of malaria, their phenotype will be highlighted in yellow.

Genotype Visual

Representation of Genotype Phenotype

HbAHbAHbAHbANormal Red Blood Cells (RBCs)--MALARIA

HbAHbAHbAHbANormal Red Blood Cells (RBCs)

Human Generation 1 (Coast - Malaria)

Imagine in this population, there are 20 humans, with genotypes and phenotypes shown below. These humans live in a humid coastal region that has mosquitoes and malaria. Only HbAHbA individuals are vulnerable to malaria, and in general, about 50% of HbA homozygotes are infected with malaria.

Human Genotype Visual Representation of Genotype Phenotype

1-HbA HbAHbAHbANormal RBCs--Malaria

2- HbAHbAHbAHbANormal RBCs--Malaria

3- HbAHbAHbAHbANormal RBCs--Malaria

4- HbAHbAHbAHbANormal RBCs--Malaria

5- HbAHbAHbAHbANormal RBCs--Malaria

6- HbAHbAHbAHbANormal RBCs--Malaria

7- HbAHbAHbAHbANormal RBCs

8- HbAHbAHbAHbANormal RBCs

9- HbAHbAHbAHbANormal RBCs

10- HbAHbAHbAHbANormal RBCs

11- HbAHbAHbAHbANormal RBCs

12- HbAHbSHbAHbSNormal RBCs

13- HbAHbSHbAHbSNormal RBCs

14- HbAHbSHbAHbSNormal RBCs

15- HbAHbSHbAHbSNormal RBCs

16- HbAHbSHbAHbSNormal RBCs

17- HbAHbSHbAHbSNormal RBCs

18- HbAHbSHbAHbSNormal RBCs

19- HbSHbSHbSHbSSickle Cell Anemia

20- HbSHbSHbSHbSSickle Cell Anemia

In Generation 1, what is the per...