| Disease frequency |
400 million people worldwide, all races; G6PD deficiency is thought to occur in approximately 60% to 70% of male Kurdish Jews, 30% of Sardinian males, 13% of Saudi males, 11% of Iranian males and 10 to 15% of African-American males |
| Carrier frequency |
1 in 4 to 1 in 20 in tropical Africa, the Middle East, tropical and subtropical Asia, some areas of the Mediterranean and Papua New Guinea |
| Inheritance |
X-linked recessive |
What is G6PD deficiency?
When the body doesn’t produce glucose-6-phosphate dehydrogenase (G6PD), an enzyme found in red blood cells, the red blood cells break down faster than they can be replenished. This results in hemolytic anemia, which can vary in severity from lifelong anemia to rare bouts to no symptoms. The anemia can also be induced by certain oxidative drugs, infections, severe stress or ingestion of fava beans. (The most severe form of the disorder is called favism, after the legume.)
G6PD deficiency is the most common known human enzyme deficiency, most frequently in areas with a high incidence of malaria, such as Africa, the Mediterranean and Southeast Asia. This is due to the fact that being a carrier for G6PD deficiency is thought to confer some resistance to malaria. Because the genetic mutations are sex-linked, most cases occur in males. Females who carry one mutation are generally not affected because the copy of the gene on the other X chromosome is functioning normally and compensates for the defect. Affected males can pass the mutation to a daughter, but it is unlikely that she would have symptoms, for this reason.
What are the most common symptoms?
Symptoms do not appear until triggered by stressors. Jaundice can manifest at birth, and is a lifelong risk. Symptoms include dark urine, paleness, difficulty breathing, a weak, rapid pulse, fatigue and yellowing of the skin and eyes. The most severe episodes are called hemolytic events, an extreme result of which can be kidney failure. However, most individuals with G6PD deficiency never know they have the condition.
Is there treatment available?
While the cause of the disorder cannot be treated, the symptoms are treatable through management of medicines and diet, and, if necessary, blood transfusions.
What is the life expectancy for someone with G6PD deficiency?
Lifespan is normal in individuals with the disorder, especially with management.
How do I find out if I am a carrier?
Carrier testing is only available to individuals with a family history of the disease. Genetic testing by full gene sequencing can detect approximately 99% of disease causing mutations. Other labs offer testing specifically for mutations found in the African population.
How is G6PD deficiency diagnosed?
A physician knowledgeable of the symptoms can order a simple blood test to check G6PD enzyme activity in the blood.
Is prenatal diagnosis available?
Testing is available to those with a previously affected child or to couples found to be at risk as carriers. This can only be performed if the familial mutation is known.
How can I find out more about G6PD deficiency?
G6PD Deficiency Favisim Association
The Association offers assistance to those affected by the G6PD enzyme deficiency by helping them protect their social rights and collect their benefits and informing and educating affected persons and the medical community on all aspects of the deficiency. This is an international site published in English, Italian, Arabic, French, German and Swedish.
G6PD Deficiency Genetic Disorder, Favism and Hemolytic Anemia Website
This website provides in-depth information for several diseases. It also has suggestions regarding living a healthy lifestyle, support groups and forums, and research information.