Author Question: Why is G6PD important for normal red cell survival? a. Hemoglobin oxygen affinity is increased in ... (Read 63 times)

jeatrice · **on:** Jun 25, 2018

Why is G6PD important for normal red cell survival?

a. Hemoglobin oxygen affinity is increased in its absence.
b. It is required to regenerate reduced glutathione.
c. It is required for insertion of iron into the protoporphyrin ring to form heme.
d. a Chains are produced in excess in its absence.

Question 2

Which of the following is a true statement regarding G6PD?

a. The gene is located on chromosome 22.
b. The gene has the greatest degree of variability in the human genome.
c. The deficiency is primarily expressed as a clinical disease in heterozygous female subjects.
d. The normal enzyme is called G6PD A.

lin77x · **Reply #1 on:** Jun 25, 2018

Answer to Question 1

ANS: B
G6PD is required to regenerate reduced glutathione in the red cell. Reduced glutathione is essential to generate nicotinamide adenine dinucleotide phosphate, which is necessary to prevent oxidative damage to the red cell.

Answer to Question 2

ANS: B
The G6PD gene has the greatest degree of variability in the human genome; this results in multiple clinical variants. The gene is found on the X chromosome, so it is only rarely clinically expressed in heterozygous female subjects who have one normal X chromosome. However, they can be shown to have varying numbers of G6PD-deficient red cells. The normal enzyme is called G6PD B. G6PD A contains one mutation so that its electrophoretic pattern is different, but it is a benign change.