G6PD deficiency is an inherited condition in which the body doesn't have enough of the enzyme glucose-6-phosphate dehydrogenase, or G6PD, which helps red blood cells (RBCs) function normally. This deficiency can cause hemolytic anemia, usually after exposure to certain medications, foods, or even infections.

Most people with G6PD deficiency don't have any symptoms, while others develop symptoms of anemia only after RBCs have been destroyed, a condition called hemolysis. In these cases, the symptoms disappear once the cause, or trigger, is removed. In rare cases, G6PD deficiency leads to chronic anemia.

With the right precautions, a child with G6PD deficiency can lead a healthy and active life.

About G6PD Deficiency

G6PD is one of many enzymes that help the body process carbohydrates and turn them into energy. G6PD also protects red blood cells from potentially harmful byproducts that can accumulate when a person takes certain medications or when the body is fighting an infection.

In people with G6PD deficiency, either the RBCs do not make enough G6PD or what is produced cannot properly function. Without enough G6PD to protect them, RBCs can be damaged or destroyed. Hemolytic anemia occurs when the bone marrow (the soft, spongy part of the bone that produces new blood cells) cannot compensate for this destruction by increasing its production of RBCs.

Causes of G6PD Deficiency

G6PD deficiency is passed along in genes from one or both parents to a child. The gene responsible for this deficiency is on the X chromosome.

G6PD deficiency is most common in African-American males. Many African-American females are carriers of G6PD deficiency, meaning they can pass the gene for the deficiency to their children but do not have symptoms; only a few are actually affected by G6PD deficiency.

People of Mediterranean heritage, including Italians, Greeks, Arabs, and Sephardic Jews, also are commonly affected. The severity of G6PD deficiency varies among these groups — it tends to be milder in African-Americans and more severe in people of Mediterranean descent.

Why does G6PD deficiency occur more often in certain groups of people? It is known that Africa and the Mediterranean basin are high-risk areas for the infectious disease malaria. Researchers have found evidence that the parasite that causes this disease does not survive well in G6PD-deficient cells. So they believe that the deficiency may have developed as a protection against malaria.

G6PD Deficiency Symptom Triggers

Kids with G6PD deficiency typically do not show any symptoms of the disorder until their red blood cells are exposed to certain triggers, which can be:

• illness, such as bacterial and viral infections
• certain painkillers and fever-reducing drugs
• certain antibiotics (especially those that have "sulf" in their names)
• certain antimalarial drugs (especially those that have "quine" in their names)

Some kids with G6PD deficiency can tolerate the medications in small amounts; others cannot take them at all. Check with your doctor for more specific instructions, as well as a complete list of medications that could pose a problem for a child with G6PD deficiency.

Other substances can be harmful to kids with this condition when consumed — or even touched — such as fava beans and naphthalene (a chemical found in mothballs and moth crystals). Mothballs can be particularly harmful if a child accidentally swallows one, so ANY contact should be avoided.

Symptoms of G6PD Deficiency

A child with G6PD deficiency who is exposed to a medication or infection that triggers the destruction of RBCs may have no symptoms at all. In more serious cases, a child may exhibit symptoms of anemia (also known as a hemolytic crisis), including:

• paleness (in darker-skinned children paleness is sometimes best seen in the mouth, especially on the lips or tongue)
• extreme tiredness
• rapid heartbeat
• rapid breathing or shortness of breath
• jaundice, or yellowing of the skin and eyes, particularly in newborns
• an enlarged spleen
• dark, tea-colored urine

Once the trigger is removed or resolved, the symptoms of G6PD deficiency usually disappear fairly quickly, typically within a few weeks.

If symptoms are mild, no medical treatment is usually needed. As the body naturally makes new red blood cells, the anemia will improve. If symptoms are more severe, a child may need to be hospitalized for supportive medical care.

Diagnosing and Treating G6PD Deficiency

In most cases, cases of G6PD deficiency go undiagnosed until a child develops symptoms. If doctors suspect G6PD deficiency, blood tests usually are done to confirm the diagnosis and to rule out other possible causes of the anemia.

If you feel that your child may be at risk because of either a family history or your ethnic background, talk to your doctor about performing a screening with blood tests to check for G6PD deficiency.

Treating the symptoms associated with G6PD deficiency is usually as simple as removing the trigger — that is, treating the illness or infection or stopping the use of a certain drug. However, a child with severe anemia may require treatment in the hospital to receive oxygen, fluids, and, if needed, a transfusion of healthy blood cells. In rare cases, the deficiency can lead to other more serious health problems.

Caring for Your Child

The best way to care for a child with G6PD deficiency is to limit exposure to the triggers of its symptoms. With the proper precautions, G6PD deficiency should not keep your child from living a healthy, active life.

Reviewed by: Steven Dowshen, MD
Date reviewed: November 2009