Glucose-6-phosphate dehydrogenase deficiency (G6PD deficiency) is an X chromosome-linked recessive genetic condition.

45. Glucose-6-phosphate dehydrogenase deficiency (G6PD deficiency) is an X chromosome-linked recessive genetic condition. It predisposes individuals with the allele (Xd) to hemolysis or destruction of red blood cells and therefore low red blood cell counts (jaundice) as opposed to the normal X allele (XG). Like sickle cell anemia, however, G6PD deficient individuals have some resistance to malaria. Drawing upon the information supplied here and your knowledge of sickle cell anemia, answer the following questions.

a. Which genotype(s) should be most likely to manifest the phenotype of low blood cell counts? (2 marks)

b. Which genotype(s) should have the highest fitness in regions where malaria is present? (2 marks)

c. Which genotype(s) should have the highest fitness in regions where malaria is absent? (2 marks)

d. In which human populations would you expect G6PD deficiency alleles to be most prevalent? Name the geographic region(s). (1 mark)