Glucose-6-Phosphate Dehydrogenase Deficiency

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is an enzymatic disorder in the pentose phosphate pathway, resulting in a deficiency that impairs the antioxidant defense mechanisms in red blood cells. This deficiency can lead to hemolytic anemia.

It is estimated that approximately 400 million people worldwide have G6PD deficiency. This deficiency is particularly common in the Mediterranean, Africa and Southeast Asia.

Epidemiological studies have demonstrated an association between malaria and G6PD deficiency. This has led to a higher prevalence of G6PD deficiency in regions where malaria is endemic.

The G6PD enzyme plays a key role in the pentose phosphate pathway by generating reduced nicotinamide adenine dinucleotide phosphate (NADPH). NADPH maintains glutathione (GSH) in its reduced form through the action of glutathione reductase, thereby providing protection against oxidative stress.

In the case of deficiency, hydrogen peroxide (H₂O₂) and superoxide reactive oxygen species accumulate, leading to hemolysis of red blood cells. This results in damage to the cell membrane and subsequent rupture of erythrocytes.

G6PD deficiency is often asymptomatic but can trigger hemolytic crises upon exposure to oxidative stress-inducing factors. Clinical manifestations include:

1. Acute hemolytic anemia: Fatigue, jaundice, dark urine.

2. Neonatal jaundice: Can occur in newborns and may lead to severe bilirubin accumulation.

3. Chronic hemolytic anemia: Rare, but some patients may exhibit persistently low red blood cell levels.[3]

1. Medications: Antimalarials, certain antibiotics and analgesics.

2. Foods: Fava beans and certain legumes.

3. Infections: Increased oxidative stress during the body’s immune response.

The diagnosis of G6PD deficiency is typically made through enzyme activity testing. Genetic testing and blood tests performed during hemolytic episodes can also aid in diagnosis.

It is essential for patients to avoid factors that increase oxidative stress. In the event of a hemolytic crisis, supportive treatment is administered, including fluid replacement, oxygen support and, if necessary, blood transfusion.