Sickle-cell anemia is an interesting genetic disease. Normal homozygous individials (SS) have normal blood cells that are easily infected with the malarial parasite. Thus, many of these individuals become very ill from the parasite and many die. Individuals homozygous for the sickle-cell trait (ss) have red blood cells that readily collapse when deoxygenated. Although malaria cannot grow in these red blood cells, individuals often die because of this genetic defect causes deformation of red blood cells. However, individuals with the heterozygous condition (Ss) have some sickling of red blood cells, but generally not enough to cause mortality. In addition, malaria cannot survive well within these "partially defective" red blood cells. Thus, heterozygotes tend to survive better than either of the homozygous conditions. Assuming HWE, if 9% of an African population is born with a severe form of sickle-cell anemia (ss), what percentage of the population will be more resistant to malaria because they are heterozygous (Ss) for the sickle-cell gene?

Sickle-cell anemia is an interesting genetic disease. Normal homozygous individials (SS) have normal blood cells that are easily infected with the malarial parasite. Thus, many of these individuals become very ill from the parasite and many die. Individuals homozygous for the sickle-cell trait (ss) have red blood cells that readily collapse when deoxygenated. Although malaria cannot grow in these red blood cells, individuals often die because of this genetic defect causes deformation of red blood cells. However, individuals with the heterozygous condition (Ss) have some sickling of red blood cells, but generally not enough to cause mortality. In addition, malaria cannot survive well within these "partially defective" red blood cells. Thus, heterozygotes tend to survive better than either of the homozygous conditions. Assuming HWE, if 9% of an African population is born with a severe form of sickle-cell anemia (ss), what percentage of the population will be more resistant to malaria because they are heterozygous (Ss) for the sickle-cell gene?

Human Heredity: Principles and Issues (MindTap Course List)

11th Edition

ISBN:9781305251052

Author:Michael Cummings

Publisher:Michael Cummings

Chapter11: Genome Alterations: Mutation And Epigenetics

Section: Chapter Questions

Problem 16QP: Familial retinoblastoma, a rare autosomal dominant defect, arose in a large family that had no prior...

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In a region of Africa, where malaria is prevalent, 40% of the population are found to have sickle-cell anemia. The disease is caused by an abnormal hemoglobin that is found in both homozygotes (S2S2) and heterozygotes (S1S2). Many homozygotes (S2S2) suffer from anemia and often die. Heterozygotes (S1S2) incur a much less debilitating malady called "sickling trait". Approximately 3% of the people with abnormal hemoglobin are homozygotes (1.2\% of the entire population). The fitness of the S2S2 homozygotes is only 1/4 that of the heterozygotes. Where malaria is prevalent, heterozygotes exhibit overdominance with respect to fitness. How would you calculate relative fitness of the S1S1 homozygotes if you're assuming the population is at an equilibrium frequency for S2?
Sickle-cell disease (often called sickle-cell anemia) is a disease that is caused by a mutation to the gene that is responsible for producing the protein hemoglobin. Remember that hemoglobin is a protein in the red blood cells which is responsible for carrying oxygen throughout the body. When a person possesses the mutated hemoglobin allele, their red blood cells take on an altered shape and this results in a variety of symptoms ranging from general weakening of the body, damage to the organs and even death. The sickle cell allele is recessive to the healthy allele, thus only individuals that are homozygous for the recessive allele will have sickle-cell disease. Individuals that are homozygous for the healthy allele, along with heterozygous, individuals will be physically healthy. Question: Given that this mutated allele will cause disease and death in individuals, what would you predict to occur to the frequency of this allele in the population? Explain.
In recent years, the country of Zambia in Africa has had increasing cases of malaria. If 8 % of the population is born with a severe form of sickle-cell anemia (ss), what percentage of the population will be more resistant to malaria because they are heterozygous (Ss) for the sickle-cell gene, under the Hardy-Weinberg assumption?
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One of your patients, a six-year-old girl who suffers from Sickle cell anemia, an inherited blood disorder in which red blood cells are abnormally shaped and fragile, leading to a short supply of red blood cells. These abnormal cells can also get stuck in small vessels, which prevent blood flow, leading to fatigue, pain, and other severe complications. Patients with sickle cell anemia produce defective beta-globin due to a point mutation that causes the change of a single amino acid residue. This is an example of what type of mutation? nonsense mutation missense mutation frameshift mutation deletion mutation
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