It's a blood test that measures the amount of glucose-6-phosphate dehydrogenase (G6PD) in your body. G6PD is an enzyme that helps your red blood cells work properly. If your G6PD level is too low, you may have G6PD deficiency, which can lead to hemolytic anemia. That's when your red blood cells die faster than your body can replace them.
G6PD protects your red blood cells from too many free radicals, which are unstable molecules that react with other molecules. Your body normally makes free radicals, but too many can be harmful. G6PD makes chemicals that stop free radicals from building up in your blood. When free radicals build up, they can damage your cells.
What Is G6PD Deficiency?
When you have low amounts of G6PD, you have G6PD deficiency. It's a hereditary condition caused by a mutation, or a change, in your G6PD gene. This gene tells your body to make the G6PD enzyme, so a mutation lessens the amount of it in your body.
G6PD deficiency is relatively common, and most people have no symptoms. Symptomatic G6PD deficiency is more common in men and people of African, Asian, and Mediterranean heritage.
G6PD deficiency may lead to hemolytic anemia and other serious health issues, but that's not always the case. G6PD deficiency alone isn't enough to cause anemia or problems with your red blood cells. But if you already have this mutation, you may have symptoms triggered by outside sources. These triggers may increase free radicals in your body. When you don't have enough G6PD to clear them, you can get sick.
Triggers may include:
- Eating fava beans
- Inhaling pollen from a fava plant
- Viral infections
- Bacterial infections
- Some antibiotics
- Some sulfa medicines
- Malaria medicines
- Acetylsalicylic acid, or aspirin
- Acetaminophen
Fava beans have certain chemicals that quickly turn into free radicals. People with G6PD deficiency can have a reaction to fava beans that causes sudden onset hemolytic anemia, a condition called favism.
G6PD deficiency in babies
If your child is born with jaundice, or yellow skin and eyes, they might have G6PD deficiency. It's common for babies to have jaundice in the first few days of life. But if jaundice lasts longer than two weeks and they have dark urine, pale stools, and high bilirubin levels, your doctor might test them for G6PD deficiency.
Why You Might Need the G6PD Test
Your doctor might order a G6PD test if you have:
- Severe tiredness
- Pale skin
- Shortness of breath
- Fast heartbeat
- Yellow skin
- Yellow eyes
- Dark urine
- Enlarged spleen
- Back pain
- Belly pain
- Weakness
- Confusion
G6PD test price
Without insurance, a G6PD test may cost $50-$300. Some insurance plans cover the cost, while others require copays or have limits on how much they cover. Your price may vary based on where you live, the health care provider or medical facility doing the test, and the type of G6PD test you have. Also consider the costs of possible follow-up tests or further medical appointments. Ask your doctor if they know of cost assistance programs that may help lower the cost of your G6PD testing.
G6PD Test Procedure
Your health care provider will take a blood sample through a needle inserted into one of your veins, usually in your arm. They'll then remove the needle and cover that area with a bandage. The procedure takes less than five minutes and is usually almost painless.
For babies, their blood sample is taken by pricking their heel. The area may bruise slightly, but it heals quickly.
G6PD Test Results
Test results are different for everyone. They might also be different depending on the lab. There are some general results, though.
Normal. A normal test result means you have enough of the enzyme and don't have G6PD deficiency. A normal measurement is 5.5-20.5 units/gram of hemoglobin for adults.
Moderate deficiency. A moderate deficiency means the amount of G6PD enzyme in your blood is at 10%-60% of the normal range. Someone with a moderate G6PD deficiency might have hemolytic anemia that comes and goes. It is usually linked to your medications or an infection.
Severe deficiency. A severe deficiency means you have less than 10% of the normal range of G6PD enzymes in your blood. If you have a severe deficiency, you might have ongoing hemolytic anemia. Sometimes, people with severe deficiency may have anemia that comes and goes.
Treatment for G6PD Deficiency
Most people with G6PD are asymptomatic, and most people who have symptoms only have them when they are under increased oxidative stress from medication or infection. You can manage the condition by avoiding triggers. This will stop you from developing hemolytic anemia.
You will want to:
- Avoid acetaminophen and aspirin
- Avoid fava beans
- Avoid certain antibiotics
- Avoid malaria medication
- Treat infections right away
Most people who have hemolysis don't have any symptoms. If you have mild symptoms, your doctor might suggest folic acid and iron pills. If hemolysis leads to anemia, you might need a blood transfusion and oxygen therapy.
While antioxidants do fight free radicals, they may not be helpful for this condition. Antioxidants such as vitamin E don't help with G6PD deficiency.
If you have G6PD deficiency, make sure to talk to your doctor about your medical history and any symptoms you're having.
Takeaways
Glucose-6-phosphate dehydrogenase (G6PD) is an enzyme that helps your red blood cells work like they should. G6PD deficiency can sometimes combine with certain triggers to cause hemolytic anemia. That's when your red blood cells die faster than your body can replace them.
G6PD FAQs
What is the G6PD normal range?
A normal measurement is 5.5-20.5 units/gram of hemoglobin for adults.
What if G6PD is high?
More often seen in older people, high G6PD may be a sign of underlying health problems.
Is G6PD a serious disease?
It's not a disease, but an enzyme. The G6PD test measures the amount of this enzyme in your blood. Having too little of it may lead to serious health issues.
What is the main cause of G6PD?
G6PD is an enzyme everyone has. A G6PD deficiency is most often caused by a genetic mutation.
What are G6PD foods to avoid?
If you have G6PD deficiency, try to avoid fava beans, legumes, bitter melon, artificial food dyes, refined sugar, high-fructose corn syrup, tonic water, and foods or drinks containing sulfites.