Sickle Cell Anemia and Thalassemias

Question 1

Sickle Cell Anemia
Amino acid 6 in the beta chain of hemoglobin has been mutated from [1] to [2]

Note: in Hemoglobin C disease, the same amino acid is mutated to [3]. This is less severe

Answer 1

[1] Glu
[2] Val
[3] Lys

Question 2

HbS preferentially favors self assembly (into crystalline strands and fibers) when HbS is in the [1] form.

Answer 2

[1] deoxy

Question 3

Sickle Cell Anemia can be treated with [1] that increases the amount of fetal hemoglobin in the body. This disrupts the polymerization process (which occurs in the beta subunit).

Answer 3

[1] hydroxyurea (Imara)

Question 4

The hemoglobin chain in the first 12 weeks of gestation is [1].

Answer 4

[1] zeta - epsilon

• • then alpha - gamma
• • then alpha - beta (delta)

Question 5

Hereditary Persistence of Fetal Hemoglobin (FPFH):
There is a defect in the gene that makes it less likely to switch from producing [1] to [2]
Gene editing techniques can utilize this to alleviate different beta-globinopathies

Answer 5

[1] gamma-globin

[2] beta-globin

Question 6

Methemoglobinemias:
oxidation of the iron in the heme from 2+ to 3+
enzyme in the RBC called [1] reduces met-Hb back to Hb
decrease in NADH can also be an issue
[2]-colored blood and blue tint in mucous membrane
drug used to treat is called [3]

Answer 6

[1] Diaphorase I (NADH-cytochrome b5 reductase)
[2] chocolate
[3] methylene blue (ironically to reduce iron back)

Question 7

[1]:
world’s most common single-gene disorder
mutation that diminishes the production of one of the two chains in hemoglobin

Answer 7

[1] Thalassemia

Question 8

Bo Thalassemia = [1]

B+ Thalassemia = [2]

Answer 8

[1] abolish beta globin synthesis

[2] reduced beta globin synthesis

Question 9

Bo Thalassemia is also known as [1].
ineffective erythropoiesis
heart failure in 2nd or 3rd decade of life

Answer 9

[1] Beta-Thalassemia Major or Cooley’s Anemia

Question 10

Alpha Thalassemia:
Defect in 1 of 4 genes - silent carrier
Defect in 2 of 4 genes - thalassemia minor
Defect in 3 of 4 genes - [1]
Defect in 4 of 4 genes - [2]

Answer 10

[1] Hemoglobin H Disease (severe anemia)

[2] Hydrops Fetalis (Thalassemia Major…dies in utero)