Glucose-6-phosphate dehydrogenase deficiency
Key points
- G-6-PD deficiency is a hereditary, sex-linked enzyme defect that results in the breakdown of red blood cells when the person is exposed to the stress of infection or certain drugs.
- G-6-PD deficiency is an inheritable, X-linked recessive disorder whose primary effect is the reduction of the enzyme G-6-PD in red blood cells, causing destruction of the cells, called hemolysis.
- Note: Severe hemolysis may cause hemoglobinuria (hemoglobin in the urine).
- Treatment If the cause is an infection, it should be treated.
Alternative names
G-6-PD deficiency; Hemolytic anemia due to G6PD deficiency; Anemia - hemolytic due to G6PD deficiency
Definition
G-6-PD deficiency is a hereditary, sex-linked enzyme defect that results in the breakdown of red blood cells when the person is exposed to the stress of infection or certain drugs.
Causes, incidence, and risk factors
G-6-PD deficiency is an inheritable, X-linked recessive disorder whose primary effect is the reduction of the enzyme G-6-PD in red blood cells, causing destruction of the cells, called hemolysis. Ultimately, this hemolysis leads to anemia - either acute hemolytic or a chronic spherocytic type.
In the United States, many more black than white people have the disorder. Approximately 10-14% of the black male population is affected. The disorder may occasionally affect a black women to a mild degree (depending on their genetic inheritance).
People with the disorder are not normally anemic and display no evidence of the disease until the red blood cells are exposed to an oxidant or stress.
Drugs that can bring on this reaction include:
- antimalarial agents
- sulfonamides (antibiotic)
- aspirin
- nonsteroidal anti-inflammatory drugs (NSAIDs)
- nitrofurantoin
- quinidine
- quinine
- others
It can also be caused by exposure to certain chemicals, such as those in mothballs. The chronic spherocytic anemia is unaffected by exposure to these drugs.
The risk of acute hemolytic crisis can be decreased by reviewing the family history for any evidence of hemolytic anemias or spherocytosis or testing before giving any medications belonging to the above class of chemicals.
The episodes are usually brief, because newly produced (young) red blood cells have normal G6PD activity.
Risk factors are being black, being male, or having a family history of G6PD deficiency. Another type of this disorder can occur 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.
Symptoms
- Fatigue
- Paleness
- Shortness of breath
- Rapid heart rate
Written and revised by
David Cohen, M.D.
Our doctors write and review articles for accuracy and keep them up to date.
health.am provides general information, not medical advice. Always consult a qualified health professional about your own health.