Your browser does not support javascript:   Search for gard hereSearch for news-and-events here.

Diseases

Genetic and Rare Diseases Information Center (GARD)

Print friendly version

Glucose-6-phosphate dehydrogenase deficiency


Other Names for this Disease
  • G6PD deficiency
  • Hemolytic anemia due to G6PD deficiency
See Disclaimer regarding information on this site. Some links on this page may take you to organizations outside of the National Institutes of Health.

Overview



What is glucose-6-phosphate dehydrogenase (G6PD) deficiency?

What are the signs and symptoms of glucose-6-phosphate dehydrogenase (G6PD) deficiency?



What causes glucose-6-phosphate dehydrogenase (G6PD) deficiency? 

How is glucose-6-phosphate dehydrogenase (G6PD) deficiency inherited?

How might glucose-6-phosphate dehydrogenase (G6PD) deficiency be treated?


What is glucose-6-phosphate dehydrogenase (G6PD) deficiency?

Glucose 6 phosphate dehydrogenase (G6PD) deficiency is a hereditary condition in which red blood cells break down (hemolysis) when the body is exposed to certain foods, drugs, infections or stress. This condition occurs when a person is missing or doesn't have enough glucose-6-phosphate dehydrogenase, an enzyme which helps red blood cells work properly.[1][2] G6PD deficiency is more likely to occur in males, particularly African Americans, and those from certain parts of Africa, Asia, and the Mediterranean. This condition is inherited in an X-linked recessive manner and is caused by mutations in the G6PD gene.[1]
Last updated: 10/11/2011

What are the signs and symptoms of glucose-6-phosphate dehydrogenase (G6PD) deficiency?

Individuals with G6PD deficiency do not display signs of the disease unless their red blood cells are exposed to certain chemicals in food or medicine, certain bacterial or viral infections, or to stress.[1][2] Many people with this condition never experience symptoms.[2] The most common medical problem associated with G6PD deficiency is hemolytic anemia, which occurs when red blood cells are destroyed faster than the body can replace them. This type of anemia leads to paleness, yellowing of the skin and whites of the eyes (jaundice), dark urine, fatigue, shortness of breath, enlarged spleen, and a rapid heart rate.[1][2]

Researchers believe that carriers of a mutation in the G6PD gene may be partially protected against malaria, an infectious disease carried by a certain type of mosquito. A reduction in the amount of functional glucose-6-dehydrogenase appears to make it more difficult for this parasite to invade red blood cells. Glucose-6-phosphate dehydrogenase deficiency occurs more frequently in areas of the world where malaria is common.[2]
Last updated: 10/11/2011

What causes glucose-6-phosphate dehydrogenase (G6PD) deficiency? 

Glucose 6 phosphate dehydrogenase (G6PD) deficiency is caused by mutations in the G6PD gene. This gene provides instructions for making an enzyme called glucose-6-phosphate dehydrogenase, which is involved in the normal processing of carbohydrates. This enzyme also protects red blood cells from the effects of potentially harmful molecules called reactive oxygen species. Reactive oxygen species are byproducts of normal cellular functions. Chemical reactions involving glucose-6-phosphate dehydrogenase produce compounds that prevent reactive oxygen species from building up to toxic levels within red blood cells.[2]

Mutations in the G6PD gene reduce the amount of glucose-6-phosphate dehydrogenase or alter its structure, which means that this enzyme can no longer play its protective role. As a result, reactive oxygen species can accumulate and damage red blood cells. Factors such as infections, certain drugs, or eating fava beans can increase the levels of reactive oxygen species, causing red blood cells to be destroyed faster than the body can replace them. A reduction in the amount of red blood cells causes the signs and symptoms of hemolytic anemia.[2]
Last updated: 10/11/2011

How is glucose-6-phosphate dehydrogenase (G6PD) deficiency inherited?

G6PD deficiency is inherited in an X-linked recessive pattern. The gene associated with this condition is located on the X chromosome, which is one of the two sex chromosomes. In males (who have only one X chromosome), one altered copy of the gene in each cell is sufficient to cause the condition. In females (who have two X chromosomes), a mutation would have to occur in both copies of the gene to cause the disorder. Because it is unlikely that females will have two altered copies of this gene, males are affected by X-linked recessive disorders much more frequently than females. A striking characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons.[2]
Last updated: 10/11/2011

How might glucose-6-phosphate dehydrogenase (G6PD) deficiency be treated?

The most important aspect of management for G6PD deficiency is to avoid agents that might trigger an attack. In cases of acute hemolytic anemia, a blood transfusion or even an exchange transfusion may be required.[3]

The G6PD Deficiency Association, which is an advocacy group that provides information and supportive resources to individuals and families affected by G6PD deficiency, provides a list of drugs and food ingredients that individuals with this condition should avoid. They also maintain a list of low risk drugs that are generally safe to take in low doses.
Last updated: 1/23/2014

References
  1. Dugdale DC, Mason JR. Glucose-6-phosphate dehydrogenase deficiency . MedlinePlus. March 2010; http://www.nlm.nih.gov/medlineplus/ency/article/000528.htm. Accessed 10/11/2011.
  2. Glucose-6-phosphate dehydrogenase deficiency. Genetics Home Reference (GHR). May 2006; http://www.ghr.nlm.nih.gov/condition/glucose-6-phosphate-dehydrogenase-deficiency. Accessed 10/11/2011.
  3. Ducrocq R. Glucose-6-phosphate-dehydrogenase deficiency. Orphanet. 2004; http://www.orpha.net/consor/cgi-bin/OC_Exp.php?Lng=EN&Expert=362. Accessed 10/11/2011.