G6PD Test

Why this test may be ordered

• If you have symptoms of hemolytic anemia, such as fatigue, pale skin, jaundice, rapid heart rate, shortness of breath, or dark urine.
• If your newborn has jaundice that doesn't go away in two weeks and is not caused by another condition.
• If you have a family history of G6PD deficiency.

Preparation and collection

No special preparations are needed for this test.

A blood sample is taken from a vein in your arm using a small needle. For newborns, a small needle is used to poke the heel and collect a few drops of blood.

There is very little risk. You may have slight pain or bruising at the needle site, which usually goes away quickly. For newborns, a small pinch and bruise may occur at the heel puncture site and should resolve quickly.

Understanding results

Your test results will show the amount of G6PD in your blood. Your healthcare provider will interpret the results based on your personal health history and exposure to triggers.

• Lower than normal amount of G6PD: You have G6PD deficiency. Your symptoms and risk of getting hemolytic anemia can vary depending on your health history and exposure to triggers. Limitation: The test result may need to be repeated if it was done during an episode of hemolytic anemia. A single result does not predict severity. Next step: Work with your healthcare provider to identify and avoid triggers such as fava beans, certain medications (e.g., antibiotics, anti-malarial drugs, NSAIDs), and infections.
• Slightly lower than normal amount of G6PD (in women): You may be a carrier of G6PD deficiency. You have one defective G6PD gene and one normal gene, so you might not have symptoms but can pass the defective gene to your children. Limitation: Your normal G6PD genes usually make enough healthy red blood cells, so you may not have symptoms. Male children are more likely to develop symptoms than female children. Next step: Talk to your healthcare provider about genetic counseling and family planning to understand the risk of passing the condition to your children.
• Normal amount of G6PD (in men): It is unlikely that you have G6PD deficiency. If you have anemia, it may be due to another cause. Limitation: If the test was done during an episode of hemolytic anemia, the result might not be accurate and your provider may recommend repeating the test in a few weeks. Next step: Follow up with your healthcare provider to determine the cause of any anemia or other symptoms you may have.

• Your symptoms and risk of getting hemolytic anemia can vary, depending on your personal health history and exposure to triggers.
• If you are a woman with slightly lower than normal G6PD, you may be a carrier and might not have symptoms, but you can still pass the defective gene to your children.
• If the test is performed during an episode of hemolytic anemia, the results may be affected and your provider may want to repeat the test in a few weeks.

What to do next

Most people with G6PD deficiency can manage their condition by avoiding triggering substances. Work with your healthcare provider to identify which substances to avoid (e.g., fava beans, certain antibiotics, anti-malarial drugs, NSAIDs). If you are a carrier, consider genetic counseling. Follow up as recommended by your provider.

• What are the common triggers I should avoid if I have G6PD deficiency?
• If I am a carrier, what is the chance that my children will inherit G6PD deficiency?
• Should I avoid any specific medications or foods on a regular basis?

Evidence source

U.S. National Library of Medicine: G6PD Test