G6PD Deficiency and Adoption from Cambodia

By Linda K. Snelling, MD

The occurence and treatment of G6PD deficiency in children adopted from Cambodia.

Kids with G6PD deficiency are normal kids. G6PD deficiency by itself does not cause illness. G6PD is just an enzyme in the red blood cells which is involved in metabolism of some drugs and other substances.   People with G6PD deficiency may have a hemolytic reaction if they take certain drugs. The reaction may make them sick, but complete recovery is the expected outcome. Most people never have any problems - especially not if they know they have it - they just don't take the drugs which can cause hemolysis. The best reason to know whether your child has G6PD deficiency is so you can avoid giving him the drugs which may cause the hemolytic reaction.

The abnormal G6PD gene is common in Cambodian people. The G6PD enzyme is determined by the X chromosome, and males are at risk because they have only 1 X-chromosome. If they get an abnormal G6PD gene on their one X - they have G6PD deficiency. Girls do not need to be tested. Females have 2 X-chromosomes, so if they get one abnormal G6PD gene, they still have a normal one on the other X. It is not likely that a girl will get 2 abnormal genes. G6PD deficiency in Cambodian children is not the same as G6PD deficiency in African American children. It is a different variant of the enzyme, and there is a slightly increased chance of hemolysis.

G6PD deficiency can be diagnosed easily by a blood test that measures the enzyme in the red blood cells. If the occurrence of a hemolytic reaction is the event which prompts testing for G6PD deficiency, it is important to know that the new immature red cells (which are stimulated by anemia) have a higher level of enzyme than the usual cells, so if the test is "iffy" (not diagnostic) it should be repeated after a few weeks.  If your child was well when tested, and the test is negative, the child does not need to be retested and does not have G6PD deficiency.

What is a hemolytic reaction?& With G6PD deficiency, certain drugs and toxins are not metabolized normally, and substances build up which cause the red blood cells to break apart in the blood (hemolysis). This usually starts 1-3 days after the drugs or toxins are taken. A hemolytic reaction can cause fever, lack of energy, anemia, increased bilirubin (jaundice), and hemoglobinuria (hemoglobin from inside the red cells spills into the urine, making the urine look dark, like coca cola). Common drugs which may cause the problem are Septra or Bactrim, two names for a drug often prescribed for ear infections, and aspirin. Some other drugs (malaria drugs) and moth balls also are known to cause reactions. 

Sometimes a reaction is mild and not even noticed. When a reaction occurs, there is no "antidote". The treatment is to stop the drug and support the child with i.v. fluids, sometimes blood transfusions, and other common treatments if indicated. Children usually recover just fine.Very rarely, a child may develop a hemolytic reaction to a common infection. However, if your child with G6PD deficiency has a cold, fever and low energy, probably he just has a virus and not a hemolytic reaction.

A hemolytic reaction can be diagnosed reliably with common blood tests.   If there is no hemolysis on the tests, the child does not have it. Because treatment for this condition is not needed (except during problematic hemolytic reactions) is no urgency to test a healthy child.  The test probably should be done, eventually, but can be scheduled with other routine blood work (lead tests etc.) so that a child does not need to be stuck for blood for this test alone. You can have it done with the first screening blood work, or later if the lab does not get enough blood. Septra and Bactrim are commonly prescribed drugs, but there are many alternatives if your child has a common infection and you do not know his G6PD "status".