G6PD

What is G6PD?

Glucose-6-Phosphate Dehydrogenase

• Enzyme involved HMP Shunt, which regenerate TPNH for the reduction of oxidized glutathione

What are the effects of Deficiency in G6PD?

• When the cells are exposed to oxidizing agents, the cells re unable to generate reduced NADP rapidly enough to combat the effects oxidizing drugs

• Leads to anemia caused by RBC hemolysis

How is the G6PD Spot Test Generally performed?

1) The reaction mixture containing G6PD + NADP + blood is incubated for a few min.

2) Drops of this mixture are then spotted onto filter paper at several time intervals

3) The spots are then visually inspected under long wave UV light

4) Development of fluorescence will be present in normal blood but will be absent due to G6PD Deficiency

How does this Disease present based on Sex of the patient? Why?

This is sex-linked inherited disease (on X chromosome); therefore:

• Males are fully expressed

• Females are usually affected in one of the X chromosome

  • May present as 2 populations (normal and deficient)

What can cause Erroneous Results?

• Excessive leukocyte number exceeding 20,000 cells/mL

• Excessive platelets

• Increased Hb (i.e., newborns)

• Decreased Hct (<20%)

• Reticulocytes due to the higher G6PD concentrations

• Unreliable control results

• Recently transfused patients