Glucose-6-Phosphate Dehydrogenase (G-6-PD) Test

The G6PD test measures the activity of Glucose-6-Phosphate Dehydrogenase (G6PD), an enzyme in red blood cells that produces NADPH, helping protect RBCs from oxidative damage and maintain their normal function.

A deficiency in G6PD makes red blood cells vulnerable to destruction during oxidative stress caused by certain foods, medications, or infections, leading to hemolytic anemia.

G6PD deficiency is one of the most common enzyme deficiency disorders worldwide and is an X-linked genetic condition, primarily affecting males, although females can be carriers and may also develop symptoms.

Who should get this test done?

This test is recommended for individuals who:

●     Have unexplained episodes of jaundice or anemia, especially after illness, medication use, or dietary changes.

●     Have a family history of G6PD deficiency or hereditary hemolytic anemia.

●     Are newborns with neonatal jaundice, particularly in regions where G6PD deficiency is common.

●     Are being prescribed medications that may cause oxidative stress, such as antimalarials, nitrofurantoin, or certain antibiotics.

●     Experience dark urine, fatigue, or pallor after consuming fava beans or certain medications.

Why consider this test?

Testing for G6PD deficiency is important because the condition may remain asymptomatic until triggered. Key reasons for testing include:

●     Diagnosing G6PD deficiency as a cause of unexplained hemolytic anemia or jaundice.

●     Identifying triggers of hemolytic episodes, such as certain medications (e.g., antimalarials, sulfonamides), fava beans, or infections.

●     Newborn screening to detect the condition early and prevent complications from neonatal jaundice.

●     Pre-medication screening before prescribing drugs that may trigger hemolysis in G6PD-deficient individuals.

●     Carrier detection to identify female carriers who may pass the condition to their children.

More Information

G6PD deficiency is the most common enzyme deficiency disorder worldwide, affecting over 400 million people, with highest prevalence in malaria-endemic regions. Being X-linked, it predominantly affects males, though females can be carriers and sometimes symptomatic. The condition is often silent until triggered by specific medications, fava beans, or infections, making prior knowledge of G6PD status critically important -  especially before prescribing antimalarials or sulfonamides. In newborns, undetected deficiency can cause severe jaundice and lead to kernicterus, a serious neurological complication. There is no cure, but the condition is fully manageable through trigger avoidance.

Other names:

●     Glucose-6-Phosphate Dehydrogenase Test

●     G6PD Enzyme Assay

●     G6PD Screening Test

●     G6PD Quantitative Test

●     Heinz Body Test (related screening test)

●     RBC G6PD Test