Glucose-6-phosphate dehydrogenase deficiency (G6PD) is an inherited disease in which people are healthy most of the time, but can develop bouts of fatigue and illness under certain circumstances. These episodes are caused by the destruction of red blood cells (hemolytic anemia), and can be brought on by taking certain types of medication or by the physical stress of a viral or bacterial infection.
It should be emphasized that many people with the mutations that cause this disease do not have any symptoms.
The symptoms of hemolytic anemia include fatigue, shortness of breath, a yellow tinge to the skin and whites of the eye (jaundice), rapid heart rate, an enlarged spleen, and overall paleness. In severe episodes, people can also have brown-colored urine.
Occasionally newborns with the disease show symptoms of jaundice within the first two weeks of life.
Medications known to provoke attacks of hemolytic anemia in people with G6PD include anti-malarial drugs, common painkillers (such as aspirin or ibuprofen), and certain antibiotics. In people with particular genetic mutations, contact with fava beans and moth balls—even simply touching them—can also provoke attacks. Because of the connection with fava beans, G6PD is sometimes known as favism.
As the name implies, the disease is caused by a deficiency in an enzyme called glucose-6-phosphate dehydrogenase. A lack of this enzyme can cause red blood cells, which carry oxygen from the lungs to the rest of the body, to be destroyed faster than the body can replace them.
Please note that G6PD is inherited in an X-linked recessive pattern. Men cannot be carriers of X-linked diseases—they either have them or they don't. Because of the way they are inherited, X-linked diseases like G6PD are typically more common in men than in women.
G6PD is fairly common, more so in men than in women. Worldwide, G6PD is estimated to affect 400 million people. It is common in African populations, with 5 to 25% of males affected depending on the country. Roughly 1 in 10 African American males is affected by the disease. G6PD is also common in the Middle East (notably among Kurds and Sephardic Jews), Asia, and Papua New Guinea.
Researchers believe that G6PD is common because it offers some protection against malaria, an infectious disease carried by mosquitoes. G6PD is most common in areas where malaria is present.
Under normal circumstances, people with G6PD do not have any symptoms and require no treatment. They should carefully avoid the medications that can cause bouts of hemolytic anemia. These include anti-malarial drugs, common painkillers (such as aspirin or ibuprofen), and certain antibiotics. A health care provider can provide a complete list of these drugs. People with certain G6PD mutations should avoid eating fava beans as well.
If an episode of hemolytic anemia does occur, people with the disease often need bed rest and in severe cases, may require blood transfusions.
Once the cause of the episode is resolved (i.e. a drug is discontinued or an infection cleared up), symptoms of the disease usually subside fairly quickly. These episodes often subside without any treatment.
The prognosis for a person with G6PD is very good. They typically have no symptoms and can live a normal lifespan with a normal quality of life. In rare cases, episodes of hemolytic anemia can be fatal. Normally people with G6PD who have episodes of hemolytic anemia recover quickly with minimal treatment.
A Italian non-profit offering information and support to people with G6PD and their families. Please note that the site frequently mentions favism, which is the familiar name of a type of G6PD found in people of Mediterranean background.
Explanations of an extensive number of genetic diseases written for everyday people by the U.S. government's National Institutes of Health.
An online medical encyclopedia written using information from the U.S. National Library of Medicine, the National Institutes of Health, and other government agencies and health-related organizations.