Glucose-6-phosphate dehydrogenase (G6PD) deficiency is an inherited genetic condition affecting red blood cells. It arises when the body does not produce enough of the G6PD enzyme, or the enzyme produced does not function correctly. This deficiency makes red blood cells vulnerable to premature destruction, a process called hemolysis, when exposed to certain triggers. Supportive therapy, primarily focused on preventing these triggers and managing any resulting acute episodes, is the main approach to living with this lifelong condition.
Understanding G6PD Deficiency
The G6PD enzyme is present in nearly all cells and plays a role in carbohydrate processing, but its function in red blood cells is particularly significant. It helps produce a molecule called NADPH, which protects cells from reactive oxygen species, harmful byproducts of normal cellular functions. Without enough functional G6PD, reactive oxygen species can accumulate in red blood cells, leading to oxidative damage and their premature breakdown. This destruction of red blood cells can result in hemolytic anemia, a condition where the body cannot produce new red blood cells quickly enough to replace those being destroyed. The genetic basis of G6PD deficiency is X-linked, meaning the gene responsible is located on the X chromosome, which explains why it is more common in males.
Preventing Triggers
Preventing exposure to substances and situations that induce oxidative stress is a primary strategy for individuals with G6PD deficiency. Fava beans are a well-known food trigger, with consumption sometimes leading to a severe hemolytic reaction called favism. Other foods, such as certain legumes, blueberries, soya products, and tonic water, may also need to be avoided.
Certain medications pose a significant risk and should be avoided. Medications to avoid include:
Antimalarials (e.g., primaquine, chloroquine)
Antibiotics (e.g., sulfonamides, nitrofurantoin, quinolones)
Dapsone
Methylene blue
Rasburicase
High doses of aspirin
Environmental factors, such as naphthalene found in mothballs, can also trigger a hemolytic crisis upon exposure. Infections, including bacterial and viral illnesses, can also cause hemolytic anemia in G6PD-deficient individuals, as the body’s immune response to infection can generate oxidative species.
Managing Acute Episodes
Symptoms of an acute hemolytic crisis can include:
Yellowing of the skin and eyes (jaundice)
Dark or tea-colored urine
Fatigue
Pallor
Shortness of breath
Rapid heart rate
Dizziness
Pain in the back or abdomen
In infants, prolonged neonatal jaundice
Immediate medical attention is necessary if these symptoms appear. The first step in managing a crisis involves discontinuing the triggering agent, whether it is a medication, food, or exposure to an environmental chemical. Supportive care includes intravenous fluids to maintain hydration and help prevent kidney damage from hemoglobin released during red blood cell destruction. In more severe cases, where hemoglobin levels drop significantly, blood transfusions may be required to replenish red blood cells and alleviate severe anemia symptoms. Oxygen supplementation may also be administered if needed to address respiratory distress.
Ongoing Care and Management
Long-term management of G6PD deficiency centers on patient education and proactive health measures. Regular medical follow-ups are recommended to monitor overall health and address any concerns. Individuals with G6PD deficiency should carry a medical alert card or bracelet that identifies their condition. This ensures that medical professionals are aware of the deficiency, especially in emergency situations, which helps guide treatment decisions and avoid contraindicated medications.
It is also important for individuals to maintain a balanced diet and avoid unprescribed remedies, as some alternative treatments may contain substances that can trigger hemolysis. Informing all healthcare providers, including dentists and pharmacists, about the condition is a continuous practice to prevent inadvertent exposure to harmful substances. While G6PD deficiency is a lifelong condition, most individuals can lead relatively normal lives by understanding and avoiding their specific triggers.