Glucose-6-phosphate dehydrogenase deficiency Causes

Glucose-6-phosphatase dehydrogenase (G6PD) deficiency is a genetic condition. It is caused by one copy of a defective G6PD gene in males or two copies of a defective G6PD gene in females. The abnormal gene responsible for this inherited enzyme deficiency is located on the X-chromosome. Therefore, the illnesses associated with G6PD deficiency occur more frequently in males than females, since males only have one X-chromosome. There are different degrees of G6PD deficiency, which vary according to the magnitude of the missing enzyme.

The degree of red blood cell rupture (hemolysis) varies according to the degree of enzyme deficiency and the drug exposure. Usually, the hemolytic anemia occurs after exposure to certain compounds with oxidant properties, including certain types of drugs such as aspirin, non-steroidal anti-inflammatory drugs (NSAIDs, such as ibuprofen), certain antibiotics (such as sulphonamide, nitrofurantoin), dapsone (an antileprotic), glibenclamide (an antidiabetic) and antimalarial drugs (such as primaquine and quinine). Compounds with the property of inducing hemolysis in G6PD deficient persons are also found in the fava bean. This condition, known as favism, occurs within a day of ingestion of the fava bean. Favism can cause fever, back pain, headache, nausea, and chills.

Infections, such as pneumonia, can precipitate the hemolytic anemia in persons who are G6PD deficient. Other chemicals, such as those in mothballs, can also trigger of red blood cell destruction.

G6PD deficiency is most common in African-American males. Many African-American females are carriers of G6PD deficiency, meaning they can pass the gene for the deficiency to their children but do not have symptoms; only a few are actually affected by G6PD deficiency. People of Mediterranean heritage, including Italians, Greeks, Arabs, and Sephardic Jews, also are commonly affected. The severity of G6PD deficiency varies among these groups — it tends to be milder in African-Americans and more severe in people of Mediterranean descent.