Glucose-6-Phosphate Dehydrogenase Deficiency

Glucose-6-phosphate dehydrogenase (G-6-PD) deficiency is a hereditary (genetic) condition in which red blood cells break down when the body is exposed to certain drugs, certain foods, or the stress of a bacterial or viral infection. G-6-PD occurs most often in males and in people of African, Asian, Middle Eastern and Mediterranean decent. 

In affected individuals, a defect in an enzyme called glucose-6-phosphate dehydrogenase causes red blood cells to break down prematurely. This destruction of red blood cells is called hemolysis. As red blood cells are destroyed faster than the body can replace them, known medically as hemolytic anemia, the symptoms patients experience include paleness, shortness of breath, jaundice, fatigue and rapid heart rate.

Persons with this condition do not display any signs of the disease until their red blood cells are exposed to certain chemicals in food or medicine, or to stress.

Symptoms are more common in men and may include:

• Dark urine
• Enlarged spleen
• Fatigue
• Pale skin
• Yellowing of skin and whites of eyes (jaundice)
• Rapid heart rate
• Shortness of breath

G6PD deficiency occurs when a person is missing or doesn't have enough of an enzyme called glucose-6-phosphate dehydrogenase, which helps red blood cells work properly.

Too little G6PD leads to the destruction of red blood cells. This process is called hemolysis. When this process is actively occurring, it is called a hemolytic episode. The episodes are usually brief, because the body continues to produce new red blood cells, which have normal activity.

Red blood cell destruction can be triggered by infections, severe stress, certain foods (such as fava beans), and certain drugs, including:

• Antimalarial drugs
• Aspirin
• Nitrofurantoin
• Nonsteroidal anti-inflammatory drugs (NSAIDs)
• Quinidine
• Quinine
• Sulfa drugs

Other chemicals, such as those in mothballs, can also trigger an episode.

In the United States, G6PD deficiency is more common among blacks than whites. Men are more likely to have this disorder than women.

You are more likely to develop this condition if you:

• Are African American
• Are of Middle Eastern decent, particularly Kurdish or Sephardic Jewish
• Are male
• Have a family history of the deficiency

A form of this disorder is common in whites of Mediterranean descent. This form is also associated with acute episodes of hemolysis. Episodes are longer and more severe than in the other types of the disorder.

A blood test can be done to check the level of G6PD.

Other tests that may be done include:

• Bilirubin level
• Complete blood count, including red blood cell count
• Hemoglobin - blood
• Hemoglobin - urine
• Haptoglobin level
• LDH test
• Methemoglobin reduction test
• Reticulocyte count

Persons with G6PD deficiency must strictly avoid things that can trigger an episode. Talk to your health care provider about your medications.

Genetic counseling or testing may be available to those who have a family history of the condition.

Treatment may involve:

• Medicines to treat an infection, if present
• Stopping any drugs that are causing red blood cell destruction
• Transfusions, in some cases

Spontaneous recovery from a hemolytic episode is the usual outcome.