General Condition Information
There are no other recognized names for this condition.
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- G6PD deficiency affects about 1 in 10 African American males in the United States.
What is Glucose-6-phosphate Dehydrogenase Deficiency
Glucose-6-phosphate dehydrogenase (G6PD) deficiency is an inherited (genetic) condition that affects red blood cells. Red blood cells carry oxygen throughout your body. In babies with G6PD deficiency, red blood cells break down too quickly.
G6PD is an enzyme that helps protect red blood cells from reactive oxygen species, which can be harmful when they build up. Reactive oxygen species are normal products of the body’s processes, but at high levels, they can cause damage to red blood cells.
Normally, red blood cells break down slowly enough for the body to continuously replace them. Babies with G6PD deficiency have red blood cells that break down faster than they can be replaced, so red blood cell levels are low. This means that babies with G6PD deficiency have a harder time bringing oxygen to the body, causing the signs and symptoms of the condition.
Newborn Screening and Follow-Up
Newborn screening for G6PD deficiency requires collecting a small amount of blood from your baby’s heel. To learn more about this process, visit the Blood Spot Screening page.
Screening measures how much G6PD enzyme is in your baby’s blood. This enzyme is responsible for protecting red blood cells. Babies with a low level of this enzyme might have G6PD deficiency.
In some cases, a screening test may also look for changes in the gene that causes G6PD deficiency (called G6PD). Babies with a change in the G6PD gene may have G6PD deficiency.
If your baby’s blood spot screening result for G6PD is out-of-range, your baby’s health care provider will contact you. Together, you will discuss next steps and follow-up plans.
An out-of-range screening result usually means that your baby has the condition and that your baby needs more follow-up testing. To learn more about screening results, visit the Blood Spot Screening Results page.
Your baby may need the following tests after an out-of-range screening result:
- Blood tests
- Genetic testing using a blood sample
You should complete any recommended follow-up testing as soon as possible. Babies with this condition can have serious health problems if they are not diagnosed and treated quickly.
False-positive newborn screening results for this condition are rare. However, screening samples that are collected after a baby receives red blood cells from someone else (a red cell transfusion) will be inaccurate.
Newborn screening helps babies lead healthier lives. If your baby has an out-of-range result, follow up with your health care provider quickly. It is important to follow their instructions. Your baby may need to get treatment right away, even if they are not showing signs or symptoms. In some cases, your baby’s health care provider may decide it is best to watch (monitor) your baby to decide next steps. Careful monitoring and early treatment will help your baby stay as healthy as possible.
Some infants with G6PD deficiency may have signs and symptoms of the condition shortly after birth. In some cases, signs of G6PD deficiency do not appear until later in life, if ever. Sometimes, signs and symptoms of G6PD deficiency are triggered by infection, certain drugs, or eating fava beans.
Signs of the condition may include the following:
- Destruction of red blood cells too fast (hemolytic anemia)
- Yellow skin and eyes (jaundice; this can be severe in some newborns, and if not treated, can cause a health problem called kernicterus)
- Dark urine
- Shortness of breath
- Fast heart beat
- Large spleen (usually found during a health provider visit)
The condition is caused by a change in the G6PD gene. This gene gives the body instructions for making an enzyme that protects red blood cells.
A changed G6PD gene causes red blood cells to not be protected from reactive oxygen species. As a result, reactive oxygen species build up and damage the red blood cells in the body.
- G6PD deficiency is inherited in an X-linked recessive pattern, which means babies inherit this condition on their X‑chromosome.
- Baby girls have two X-chromosomes. Only girls with two nonworking G6PD genes (one on each chromosome) have G6PD deficiency. This is a very rare situation.
- Baby boys only have one X-chromosome. All boys with one nonworking G6PD gene (on their only X-chromosome) have G6PD deficiency. This condition is more common in boys.
- Girls with one working copy and one nonworking copy of the G6PD gene are called carriers.
- Carriers may pass down a nonworking copy of the gene to their children.
- Carriers without any symptoms are also called asymptomatic females.
- Parents who already have a boy with G6PD deficiency still have a 1 in 2 chance of having another boy with G6PD deficiency. Parents who have a girl who is a G6PD deficiency carrier still have a 1 in 2 chance of having another girl who is a G6PD deficiency carrier.
- Genetic counselors and medical geneticists can help families learn about this condition and the chance of having children with it. Visit the National Society of Genetic Counselors to find a genetic counselor and the American College of Medical Genetics and Genomics to find a medical geneticist.
Treatment and Management
It is important to talk to your health care provider about which treatment(s) are best for your baby. The goal of treatment is to prevent the health problems caused by this condition.
Treatments may include the following:
- Phototherapy to help with jaundice
- Blood transfusions in some cases
- Avoidance of fava beans or drugs that trigger anemia
Children with symptoms who receive early health care and treatment for G6PD deficiency can have healthier lives than those who do not receive treatment.