Glucose 6 Phosphate Dehydrogenase (G6PD Quantitative) Test
What is G6PD Quan.?
Glucose-6-phosphate dehydrogenase (G6PD) is an enzyme found in all the cells of the body and is involved in the production of energy. It protects the red blood cells from the by-products produced during metabolism. A deficiency of this enzyme makes the red blood cells (RBCs) more prone to breaking apart under certain conditions. The G6PD Quantitative Test measures the levels of the enzyme G6PD in blood.
Why is G6PD Quan. done?
The G6PD Quantitative Test is performed:
· To determine G6PD deficiency as the cause of hemolytic anemia
What does G6PD Quan. Measure?
Glucose-6-phosphate dehydrogenase is an enzyme present in all the cells of the body. G6PD serves to provide energy to the cells. It protects the red blood cells from the toxic by-products formed during metabolism.
G6PD deficiency creates an oxidative environment in the body which can cause large-scale breakdown of RBCs (hemolysis). This breakdown could be caused due to certain triggers such as bacterial infections, consuming fava beans, certain medicines, etc. Hemolysis is more common in the older cells as the amount of G6PD enzyme decreases with the age of RBCs.
In case of exposure to any trigger, G6PD-deficient RBCs start depositing hemoglobin in them. This leads to the formation of small granules called Heinz bodies. These RBCs containing Heinz bodies are usually removed from the blood circulation in the spleen, but in severe cases may breakdown in blood circulation itself. The body’s inability to compensate for the large-scale destruction of RBCs causes hemolytic anemia (anemia due to the breakdown of RBCs). Hemolytic anemia causes symptoms such as yellowing of skin and eyes (jaundice), weakness and difficulty in breathing.
In spite of being an evolutionary disadvantage, G6PD deficiency is prevalent worldwide in a number of different forms. G6PD deficiency is very commonly observed in malaria-prevalent regions, such as Africa, South East Asia, the Middle East and the Mediterranean. The only possible reason for this is that a person affected with the deficiency of G6PD is protected from malaria. Since malarial parasites divide and grow in the RBCs, it is considered that the rapid destruction of RBCs in the spleen removes malarial parasites quickly from the system. Also, oxidative stress has been seen to be lethal to these parasites, making them unable to survive in the oxidative body environment in G6PD deficient individuals.
Interpreting G6PD Quan. results
Normal range: 4.60 - 13.50 units/g Hb (hemoglobin)
The amount of G6PD deficiency does not directly correlate with the severity of symptoms that appear.
Those with less than 10% of the normal G6PD amount are considered severely deficient and with chronic hemolytic anemia.
Those with 10% to 60% of the normal G6PD amount are considered moderately deficient and may undergo episodes of hemolytic anemia in response to triggers.
Answers to Patient Concerns & Frequently Asked Questions (FAQs) about G6PD Quan.
Frequently Asked Questions about Glucose 6 Phosphate Dehydrogenase (G6PD Quantitative) Test